diff --git a/boot/pb/equates.h b/boot/pb/equates.h
index 7e4bf03fc..696353e18 100644
--- a/boot/pb/equates.h
+++ b/boot/pb/equates.h
@@ -1,4 +1,4 @@
-/* equates.h for Chez Scheme Version 9.9.9-pre-release.23 */
+/* equates.h for Chez Scheme Version 9.9.9-pre-release.24 */
 
 /* Do not edit this file.  It is automatically generated and */
 /* specifically tailored to the version of Chez Scheme named */
@@ -1010,7 +1010,7 @@ typedef uint64_t U64;
 #define rtd_sealed 0x4
 #define sbwp (ptr)0x4E
 #define scaled_shot_1_shot_flag -0x8
-#define scheme_version 0x9090917
+#define scheme_version 0x9090918
 #define seginfo_generation_disp 0x1
 #define seginfo_list_bits_disp 0x8
 #define seginfo_space_disp 0x0
diff --git a/boot/pb/petite.boot b/boot/pb/petite.boot
index 19d95df17..4dae5bd5d 100644
Binary files a/boot/pb/petite.boot and b/boot/pb/petite.boot differ
diff --git a/boot/pb/scheme.boot b/boot/pb/scheme.boot
index 908f14fb5..5e1f2456e 100644
Binary files a/boot/pb/scheme.boot and b/boot/pb/scheme.boot differ
diff --git a/boot/pb/scheme.h b/boot/pb/scheme.h
index 24a1418bf..d7d498a7a 100644
--- a/boot/pb/scheme.h
+++ b/boot/pb/scheme.h
@@ -1,4 +1,4 @@
-/* scheme.h for Chez Scheme Version 9.9.9-pre-release.23 (pb) */
+/* scheme.h for Chez Scheme Version 9.9.9-pre-release.24 (pb) */
 
 /* Do not edit this file.  It is automatically generated and */
 /* specifically tailored to the version of Chez Scheme named */
@@ -40,7 +40,7 @@
 #endif
 
 /* Chez Scheme Version and machine type */
-#define VERSION "9.9.9-pre-release.23"
+#define VERSION "9.9.9-pre-release.24"
 #define MACHINE_TYPE "pb"
 
 /* Integer typedefs */
diff --git a/build.zuo b/build.zuo
index 6fe5556a9..c21d2caa9 100644
--- a/build.zuo
+++ b/build.zuo
@@ -181,7 +181,8 @@
 
   (define (record-build-success token xm m host-scheme host-workarea)
     ;; record success so boot files will not be rebuilt from pb
-    (when record-from-pb?
+    (when (and record-from-pb?
+               (not (equal? xm "pb")))
       (build-boot-target token xm m host-scheme host-workarea void)))
 
   ;; used to create a target for "quickboot", or just record dependency for other modes
diff --git a/csug/objects.stex b/csug/objects.stex
index e1cf7c7fa..02b98850c 100644
--- a/csug/objects.stex
+++ b/csug/objects.stex
@@ -754,7 +754,9 @@ The length and indices of a vector in {\ChezScheme} are always fixnums.
 \index{immutable vectors}\index{mutable vectors}%
 All vectors are mutable by default, including constants.
 A program can create immutable vectors via
-\index{\scheme{vector->immutable-vector}}\scheme{vector->immutable-vector}.
+\index{\scheme{vector->immutable-vector}}\scheme{vector->immutable-vector},
+\index{\scheme{immutable-vector}}\scheme{immutable-vector},
+and other functions.
 Any attempt to modify an immutable vector causes an exception to be raised.
 
 %----------------------------------------------------------------------------
@@ -920,6 +922,22 @@ is immutable; otherwise, the result is an immutable vector with the same content
 (vector-set! v 0 0) ;=> \var{exception: not mutable}
 \endschemedisplay
 
+%----------------------------------------------------------------------------
+\entryheader
+\formdef{immutable-vector}{\categoryprocedure}{(immutable-vector \var{obj} \dots)}
+\formdef{immutable-vector-copy}{\categoryprocedure}{(immutable-vector-copy \var{vector})}
+\formdef{immutable-vector-copy}{\categoryprocedure}{(immutable-vector-copy \var{vector} \var{start} \var{n})}
+\formdef{immutable-vector-append}{\categoryprocedure}{(immutable-vector-append \var{vector} \dots)}
+\formdef{immutable-vector-set/copy}{\categoryprocedure}{(vector-set/copy \var{vector} \var{n} \var{val})}
+\listlibraries
+\endentryheader
+
+Like \scheme{vector}, \scheme{vector-copy},  \scheme{vector-append}, and
+\scheme{vector-set/copy}, but these procedures return an immutable vector instead of a mutable
+one, and they may return an existing object instead of allocating a new one.
+In the case of \scheme{immutable-vector-copy}, \scheme{immutable-vector-append}, or
+\scheme{immutable-vector-set/copy}, an argument vector can be mutable or immutable.
+
 %----------------------------------------------------------------------------
 \entryheader
 \formdef{self-evaluating-vectors}{\categorythreadparameter}{self-evaluating-vectors}
diff --git a/mats/5_6.ms b/mats/5_6.ms
index 80808b74c..c66e687c5 100644
--- a/mats/5_6.ms
+++ b/mats/5_6.ms
@@ -16,7 +16,24 @@
 (mat vector
     (equal? (vector 1 2 3 4) '#(1 2 3 4))
     (eq? (vector) '#())
- )
+    )
+
+(mat immutable-vector
+  (equal? (immutable-vector 1 2 3 4) (vector->immutable-vector '#(1 2 3 4)))
+  (eq? (immutable-vector) (vector->immutable-vector '#()))
+  (begin
+    (define (f x)
+      (let ([v (immutable-vector (begin (write 'a) (+ x 1)) (begin (write 'a) 2) (begin (write 'a) (cons 3 x)))])
+        (for-each write
+          (list
+           (begin (write 'b) (vector-ref v 0))
+           (begin (write 'b) (vector-ref v 1))
+           (begin (write 'b) (vector-ref v 2))))))
+    #t)
+  (equal?
+   (with-output-to-string (lambda () (f 7)))
+   "aaabbb82(3 . 7)")
+  )
 
 (mat make-vector
     (eqv? (vector-length (make-vector 10)) 10)
@@ -112,12 +129,16 @@
  )
 
 (mat vector-copy
-    (equal? (vector-copy '#()) '#())
+    (eq? (vector-copy '#()) '#())
     (equal? (vector-copy '#(a b c)) '#(a b c))
     (equal? (vector-copy '#(a b c) 0 1) '#(a))
     (equal? (vector-copy '#(a b c) 2 1) '#(c))
     (equal? (vector-copy '#(a b c d) 1 2) '#(b c))
     (eq? (vector-copy '#(a b c d) 1 0) '#())
+    (mutable-vector? (vector-copy '#(a b c)))
+    (mutable-vector? (vector-copy '#(a b c) 0 1))
+    (mutable-vector? (vector-copy '#(a b c) 2 1))
+    (mutable-vector? (vector-copy '#(a b c d) 1 2))
     (let* ((x1 (vector 1 2 3)) (x2 (vector-copy x1)))
         (and (equal? x2 x1) (not (eq? x2 x1))))
     (andmap
@@ -133,11 +154,41 @@
     (error? (vector-copy '#(a b c) 2 -1))
     )
 
+(mat immutable-vector-copy
+    (eq? (immutable-vector-copy '#()) (immutable-vector))
+    (equal? (immutable-vector-copy '#(a b c)) '#(a b c))
+    (equal? (immutable-vector-copy '#(a b c) 0 1) '#(a))
+    (equal? (immutable-vector-copy '#(a b c) 2 1) '#(c))
+    (equal? (immutable-vector-copy '#(a b c d) 1 2) '#(b c))
+    (immutable-vector? (immutable-vector-copy '#(a b c)))
+    (immutable-vector? (immutable-vector-copy '#(a b c) 0 1))
+    (immutable-vector? (immutable-vector-copy '#(a b c) 2 1))
+    (immutable-vector? (immutable-vector-copy '#(a b c d) 1 2))
+    (eq? (immutable-vector-copy '#(a b c d) 1 0) (immutable-vector))
+    (let* ((x1 (vector 1 2 3)) (x2 (immutable-vector-copy x1)))
+        (and (equal? x2 x1) (not (eq? x2 x1))))
+    (andmap
+      (lambda (n)
+        (let ([v (vector-map random (make-vector n 1000))])
+          (equal? (immutable-vector-copy v) v)))
+      (map random (make-list 500 2500)))
+    (error? (immutable-vector-copy '(a b c)))
+    (error? (immutable-vector-copy '#(a b c) 'x 2))
+    (error? (immutable-vector-copy '#(a b c) 1 'x))
+    (error? (immutable-vector-copy '#(a b c) -1 2))
+    (error? (immutable-vector-copy '#(a b c) 1 3))
+    (error? (immutable-vector-copy '#(a b c) 2 -1))
+    )
+
 (mat vector-set/copy
     (equal? (vector-set/copy '#(a b c) 0 'x) '#(x b c))
     (equal? (vector-set/copy '#(a b c) 1 'x) '#(a x c))
     (equal? (vector-set/copy '#(a b c) 2 'x) '#(a b x))
     (equal? (vector-set/copy '#(a b c d e f g h i) 2 'x) '#(a b x d e f g h i))
+    (mutable-vector? (vector-set/copy '#(a b c) 0 'x))
+    (mutable-vector? (vector-set/copy '#(a b c) 1 'x))
+    (mutable-vector? (vector-set/copy '#(a b c) 2 'x))
+    (mutable-vector? (vector-set/copy '#(a b c d e f g h i) 2 'x))
     (error? (vector-set/copy 1))
     (error? (vector-set/copy '#(a b c)))
     (error? (vector-set/copy '#(a b c) 1))
@@ -146,6 +197,23 @@
     (error? (vector-set/copy '#(a b c) 3 'x))
  )
 
+(mat immutable-vector-set/copy
+    (equal? (immutable-vector-set/copy '#(a b c) 0 'x) '#(x b c))
+    (equal? (immutable-vector-set/copy '#(a b c) 1 'x) '#(a x c))
+    (equal? (immutable-vector-set/copy '#(a b c) 2 'x) '#(a b x))
+    (equal? (immutable-vector-set/copy '#(a b c d e f g h i) 2 'x) '#(a b x d e f g h i))
+    (immutable-vector? (immutable-vector-set/copy '#(a b c) 0 'x))
+    (immutable-vector? (immutable-vector-set/copy '#(a b c) 1 'x))
+    (immutable-vector? (immutable-vector-set/copy '#(a b c) 2 'x))
+    (immutable-vector? (immutable-vector-set/copy '#(a b c d e f g h i) 2 'x))
+    (error? (immutable-vector-set/copy 1))
+    (error? (immutable-vector-set/copy '#(a b c)))
+    (error? (immutable-vector-set/copy '#(a b c) 1))
+    (error? (immutable-vector-set/copy '#(a b c) 'y 'x))
+    (error? (immutable-vector-set/copy '#(a b c) -1 'x))
+    (error? (immutable-vector-set/copy '#(a b c) 3 'x))
+ )
+
 (mat vector-append
     (eq? (vector-append) '#())
     (eq? (vector-append '#()) '#())
@@ -153,16 +221,41 @@
     (eq? (vector-append '#() '#() '#()) '#())
     (eq? (vector-append '#() '#() '#() '#()) '#())
     (equal? (vector-append '#(a b c)) '#(a b c))
+    (mutable-vector? (vector-append '#(a b c)))
     (equal? (vector-append '#(a b c) '#(d e)) '#(a b c d e))
+    (mutable-vector? (vector-append '#(a b c) '#(d e)))
     (equal? (vector-append '#(a b c) '#(d e) '#(f) '#(g h i)) '#(a b c d e f g h i))
+    (mutable-vector? (vector-append '#(a b c) '#(d e) '#(f) '#(g h i)))
     (equal? (vector-append (vector 'p) '#()) '#(p))
+    (mutable-vector? (vector-append (vector 'p) '#()))
     (equal? (vector-append '#() (vector 'p)) '#(p))
+    (mutable-vector? (vector-append '#() (vector 'p)))
     (equal? (vector-append (vector 'p) '#(a b c)) '#(p a b c))
     (equal? (vector-append '#(a b c) (vector 'p)) '#(a b c p))
+    (mutable-vector? (vector-append (vector 'p) '#(a b c)))
+    (mutable-vector? (vector-append '#(a b c) (vector 'p)))
+    (equal? (vector-append (vector 'p) (make-vector 3 'ok)) '#(p ok ok ok))
+    (mutable-vector? (vector-append (vector 'p) (make-vector 3 'ok)))
+    (let* ([ip (open-input-string "4 0")]
+           [c 0]
+           [v0 (vector-append (make-vector (read ip) (begin (set! c (+ c 1)) c)) (vector 'x 2 3 4))]
+           [c0 c]
+           [v1 (vector-append (make-vector (read ip) (begin (set! c (+ c 1)) c)) (vector 'y 'not))])
+      (and (equal? v0 '#(1 1 1 1 x 2 3 4))
+           (mutable-vector? v0)
+           (= c0 1)
+           (equal? v1 '#(y not))
+           (mutable-vector? v1)
+           (= c 2)))
+    (equal? (vector-append (make-vector 1 'p) '#(d q)) '#(p d q))
+    (mutable-vector? (vector-append (make-vector 1 'p) '#(d q)))
+    (equal? (vector-append (vector 'p) (make-vector 0 'ok)) '#(p))
+    (mutable-vector? (vector-append (vector 'p) (make-vector 0 'ok)))
     (error? (vector-append 1))
     (error? (vector-append '#(a b c) 'x))
     (error? (vector-append '#(a b c) '#(d) 'x))
     (error? (vector-append '#(a b c) '#(d) '#(e)'x))
+    (error? (vector-append (vector 'p) (make-vector -1 'ok)))
 
     ;; ensure that `vector-append` optimization doesn't misorder
     ;; evaluation and potential collection with respect to filling
@@ -182,6 +275,228 @@
                       (equal? (vector-ref v N) "8")))))))
  )
 
+(mat immutable-vector-append
+    (eq? (immutable-vector-append) (immutable-vector))
+    (eq? (immutable-vector-append '#()) (immutable-vector))
+    (eq? (immutable-vector-append '#() '#()) (immutable-vector))
+    (eq? (immutable-vector-append '#() '#() '#()) (immutable-vector))
+    (eq? (immutable-vector-append '#() '#() '#() '#()) (immutable-vector))
+    (equal? (immutable-vector-append '#(a b c)) '#(a b c))
+    (immutable-vector? (immutable-vector-append '#(a b c)))
+    (equal? (immutable-vector-append '#(a b c) '#(d e)) '#(a b c d e))
+    (immutable-vector? (immutable-vector-append '#(a b c) '#(d e)))
+    (equal? (immutable-vector-append '#(a b c) '#(d e) '#(f) '#(g h i)) '#(a b c d e f g h i))
+    (immutable-vector? (immutable-vector-append '#(a b c) '#(d e) '#(f) '#(g h i)))
+    (equal? (immutable-vector-append (vector 'p) '#()) '#(p))
+    (immutable-vector? (immutable-vector-append (vector 'p) '#()))
+    (equal? (immutable-vector-append '#() (vector 'p)) '#(p))
+    (immutable-vector? (immutable-vector-append '#() (vector 'p)))
+    (equal? (immutable-vector-append (vector 'p) '#(a b c)) '#(p a b c))
+    (equal? (immutable-vector-append '#(a b c) (vector 'p)) '#(a b c p))
+    (immutable-vector? (immutable-vector-append (vector 'p) '#(a b c)))
+    (immutable-vector? (immutable-vector-append '#(a b c) (vector 'p)))
+    (equal? (immutable-vector-append (vector 'p) (make-vector 3 'ok)) '#(p ok ok ok))
+    (immutable-vector? (immutable-vector-append (vector 'p) (make-vector 3 'ok)))
+    (equal? (immutable-vector-append (vector 'p) (make-vector 0 'ok)) '#(p))
+    (immutable-vector? (immutable-vector-append (vector 'p) (make-vector 0 'ok)))
+    (equal? (immutable-vector-append (make-vector 1 'p) '#(d q)) '#(p d q))
+    (immutable-vector? (immutable-vector-append (make-vector 1 'p) '#(d q)))
+    (let* ([ip (open-input-string "4 0")]
+           [c 0]
+           [v0 (immutable-vector-append (make-vector (read ip) (begin (set! c (+ c 1)) c)) (vector 'x 2 3 4))]
+           [c0 c]
+           [v1 (immutable-vector-append (make-vector (read ip) (begin (set! c (+ c 1)) c)) (vector 'y 'not))])
+      (and (equal? v0 '#(1 1 1 1 x 2 3 4))
+           (immutable-vector? v0)
+           (= c0 1)
+           (equal? v1 '#(y not))
+           (immutable-vector? v1)
+           (= c 2)))
+    (error? (immutable-vector-append 1))
+    (error? (immutable-vector-append '#(a b c) 'x))
+    (error? (immutable-vector-append '#(a b c) '#(d) 'x))
+    (error? (immutable-vector-append '#(a b c) '#(d) '#(e)'x))
+    (error? (immutable-vector-append (vector 'p) (make-vector -1 'ok)))
+
+    ;; same as mutable-vector test above
+    (with-interrupts-disabled
+      (letrec ([f (lambda (m)
+                    (collect 0 1)
+                    (number->string m))]
+               [N 1000])
+        (let ([v (immutable-vector-append (make-vector N)
+                                          (vector (f 8)))])
+          (and (eqv? 0 (#%$generation (vector-ref v N)))
+               (eqv? 0 (#%$generation v))
+               (begin
+                 (collect 0 1)
+                 (and (eqv? 1 (#%$generation (vector-ref v N)))
+                      (equal? (vector-ref v N) "8")))))))
+    )
+
+(mat vector-cbuild-cp0 (parameters [enable-cp0 #t] [#%$suppress-primitive-inlining #f])
+     (equivalent-expansion?
+      (expand/optimize '(vector->immutable-vector (vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize '(vector->immutable-vector (immutable-vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (not
+      (equivalent-expansion?
+       (expand/optimize `(vector->immutable-vector '#(1 2)))
+       `(quote ,(immutable-vector 1 2))))
+     (equivalent-expansion?
+      (expand/optimize `(vector->immutable-vector '#()))
+      `(quote ,(immutable-vector)))
+     (equivalent-expansion?
+      (expand/optimize `(vector->immutable-vector ',(immutable-vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector->immutable-vector (vector x y))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector->immutable-vector (immutable-vector x y))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector->immutable-vector (begin (x) (vector x y)))))
+      `(lambda (x y) (x) (#3%immutable-vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector->immutable-vector (begin (x) (immutable-vector x y)))))
+      `(lambda (x y) (x) (#3%immutable-vector x y)))
+
+     (equivalent-expansion?
+      (expand/optimize '(immutable-vector-copy (vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize '(immutable-vector-copy (immutable-vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize `(immutable-vector-copy ',(immutable-vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (immutable-vector-copy (vector x y))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (immutable-vector-copy (immutable-vector x y))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+
+     (equivalent-expansion?
+      (expand/optimize '(vector-copy (vector 1 2)))
+      `(#3%vector 1 2))
+     (equivalent-expansion?
+      (expand/optimize '(vector-copy (immutable-vector 1 2)))
+      `(#3%vector 1 2))
+     (equivalent-expansion?
+      (expand/optimize `(vector-copy ',(immutable-vector 1 2)))
+      `(#3%vector 1 2))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector-copy (vector x y))))
+      `(lambda (x y) (#3%vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector-copy (immutable-vector x y))))
+      `(lambda (x y) (#3%vector x y)))
+
+     (equivalent-expansion?
+      (expand/optimize '(immutable-vector-append (vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize '(immutable-vector-append (vector 1 2) (vector 3 4)))
+      `(quote ,(immutable-vector 1 2 3 4)))
+     (equivalent-expansion?
+      (expand/optimize '(immutable-vector-append (immutable-vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize '(immutable-vector-append (immutable-vector 1 2) (vector 3 4)))
+      `(quote ,(immutable-vector 1 2 3 4)))
+     (equivalent-expansion?
+      (expand/optimize `(immutable-vector-append ',(immutable-vector 1 2)))
+      `(quote ,(immutable-vector 1 2)))
+     (equivalent-expansion?
+      (expand/optimize `(immutable-vector-append ',(immutable-vector 1 2) (vector 3 4)))
+      `(quote ,(immutable-vector 1 2 3 4)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (immutable-vector-append (vector x y))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (immutable-vector-append (vector x y) (vector y x))))
+      `(lambda (x y) (#3%immutable-vector x y y x)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (immutable-vector-append (immutable-vector x y))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (immutable-vector-append (immutable-vector x y) (immutable-vector y x))))
+      `(lambda (x y) (#3%immutable-vector x y y x)))
+     (equivalent-expansion?
+      (expand/optimize `(lambda (x y) (immutable-vector-append (immutable-vector 1 x)
+                                                               (vector 2 y)
+                                                               (vector-copy (vector 6 7 x))
+                                                               ',(immutable-vector 8))))
+      `(lambda (x y) (#3%immutable-vector 1 x 2 y 6 7 x 8)))
+
+     (equivalent-expansion?
+      (expand/optimize '(vector-append (vector 1 2)))
+      `(#3%vector 1 2))
+     (equivalent-expansion?
+      (expand/optimize '(vector-append (vector 1 2) (vector 3 4)))
+      `(#3%vector 1 2 3 4))
+     (equivalent-expansion?
+      (expand/optimize '(vector-append (immutable-vector 1 2)))
+      `(#3%vector 1 2))
+     (equivalent-expansion?
+      (expand/optimize '(vector-append (immutable-vector 1 2) (vector 3 4)))
+      `(#3%vector 1 2 3 4))
+     (equivalent-expansion?
+      (expand/optimize `(vector-append ',(immutable-vector 1 2)))
+      `(#3%vector 1 2))
+     (equivalent-expansion?
+      (expand/optimize `(vector-append ',(immutable-vector 1 2) (vector 3 4)))
+      `(#3%vector 1 2 3 4))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector-append (vector x y))))
+      `(lambda (x y) (#3%vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector-append (vector x y) (vector y x))))
+      `(lambda (x y) (#3%vector x y y x)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector-append (immutable-vector x y))))
+      `(lambda (x y) (#3%vector x y)))
+     (equivalent-expansion?
+      (expand/optimize '(lambda (x y) (vector-append (immutable-vector x y) (immutable-vector y x))))
+      `(lambda (x y) (#3%vector x y y x)))
+     (equivalent-expansion?
+      (expand/optimize `(lambda (x y) (vector-append (immutable-vector 1 x)
+                                                     (vector 2 y)
+                                                     (vector-copy (vector 6 7 x))
+                                                     ',(immutable-vector 8))))
+      `(lambda (x y) (#3%vector 1 x 2 y 6 7 x 8)))
+
+     
+     (equivalent-expansion?
+      (expand/optimize `(lambda (x y)
+                          (vector-ref (vector-copy (immutable-vector 1 x)) 1)))
+      `(lambda (x y) x))
+     (equivalent-expansion?
+      (expand/optimize `(lambda (x y)
+                          (vector->immutable-vector
+                           (vector (vector-ref (vector-copy (immutable-vector 1 x)) 1)
+                                   (vector-ref (immutable-vector-append (immutable-vector 2 3)
+                                                                        (vector y 0))
+                                               2)))))
+      `(lambda (x y) (#3%immutable-vector x y)))
+
+     (equivalent-expansion?
+      (expand/optimize `(lambda (x)
+                          (vector-length (immutable-vector x x x))))
+      `(lambda (x) 3))
+     (equivalent-expansion?
+      (expand/optimize `(lambda (x)
+                          (vector-length (immutable-vector x (#2%printf "hi\n") x))))
+      `(lambda (x)
+         (#2%printf "hi\n")
+         3))
+
+     )
+
 (mat vector-fill!
     (let ([v (vector-copy '#5(a b c d e))])
        (and (equal? v '#5(a b c d e))
@@ -1452,7 +1767,14 @@
     (equal? '#(1 2 3) immutable-123-vector)
     (eq? immutable-123-vector
          (vector->immutable-vector immutable-123-vector))
-    
+
+    ;; these also turn out to be conversions that should
+    ;; leave an immutable vector alone:
+    (eq? immutable-123-vector
+         (immutable-vector-copy immutable-123-vector))
+    (eq? immutable-123-vector
+         (immutable-vector-append immutable-123-vector))
+
     (mutable-vector? (make-vector 5))
     (not (immutable-vector? (make-vector 5)))
     
diff --git a/mats/cp0.ms b/mats/cp0.ms
index dd9c5d1bd..a007cf0ff 100644
--- a/mats/cp0.ms
+++ b/mats/cp0.ms
@@ -2869,6 +2869,31 @@
                  (begin (#%write 'f) ($yyy-ok))
                  (begin (#%write 'g) ($zzz-ok))))
              (begin (#%write 'h) 3))))
+  (equivalent-expansion?
+    (parameterize ([enable-cp0 #t] [#%$suppress-primitive-inlining #f] [optimize-level 2])
+      (expand/optimize
+        '(immutable-vector 1 2 3)))
+    ''#(1 2 3))
+  (equivalent-expansion?
+    (parameterize ([enable-cp0 #t] [#%$suppress-primitive-inlining #f] [optimize-level 2])
+      (expand/optimize
+        '(lambda (x)
+           (let ([v (begin (write 'a) (immutable-vector x 2 3))])
+             (list
+               (begin (write 'b) (vector-ref v 0))
+               (begin (write 'c) (vector-ref v 1))
+               (begin (write 'd) (vector-ref v 2)))))))
+    '(lambda (x)
+       (#2%write 'a)
+       (#2%list
+         (begin (#2%write 'b) x)
+         (begin (#2%write 'c) 2)
+         (begin (#2%write 'd) 3))))
+  ((lambda (x) (and (member x '("abc" "cab")) #t))
+   (with-output-to-string
+     (lambda ()
+       (vector-ref (begin (write 'a) (immutable-vector (begin (write 'b) 123)))
+         (begin (write 'c) 0)))))
  )
 
 (mat let-pushing
@@ -2962,6 +2987,74 @@
              [n (if v v 72)])
          (#2%display "1")
          (#2%list q n))))
+  ((lambda (x ls) (and (member x ls) #t))
+   (with-input-from-string "#(0 1 2 #\\e)"
+     (lambda ()
+       (with-output-to-string
+        (lambda ()
+          (define-syntax check
+            (identifier-syntax
+             (unless (read) ;; !#eof is true
+               (raise 'issue))))
+          (display
+           (let* ([x (read)] ;; confound cp0
+                  [e (if (and (vector? x) (= (vector-length x) 4))
+                         (vector-ref x 3)
+                         (raise 'issue))]
+                  [e ((begin (write 'a) check (begin (write 'b) (lambda (x) (display x) (char-upcase x))))
+                      (begin (write 'c) check (begin (write 'd) check e)))])
+             (if (char? e)
+                 e
+                 'bad)))))))
+   '("abcdeE" "cdabeE"))
+  (equivalent-expansion?
+   (parameterize ([#%$suppress-primitive-inlining #f] [run-cp0 (lambda (cp0 x) (cp0 (cp0 x)))] [optimize-level 2])
+     (expand/optimize
+      '(let ()
+         (define-syntax <foo> ;; stripped down
+           (syntax-rules (assert copy* is? make)
+             [(_ assert e0)
+              (unless (<foo> is? e0) (raise 'bad))]
+             [(_ copy* e0 [a e1])
+              (eq? (datum a) 'a)
+              (let ([v e0])
+                (<foo> assert v)
+                (<foo> make
+                  [a (let ([a (#3%vector-ref v 1)]) e1)]
+                  [b (#3%vector-ref v 2)]))]
+             [(_ is? e0)
+              (let ([v e0])
+                (and (vector? v)
+                     (fx= (vector-length v) 3)
+                     (eq? (#3%vector-ref v 0) '<foo>)))]
+             [(_ make [a e0] [b e1])
+              (equal? (datum (a b)) '(a b))
+              (immutable-vector '<foo> e0 e1)]
+             [(_ field e0)
+              (memq (datum field) '(a b))
+              (let ([v e0])
+                (<foo> assert v)
+                (#3%vector-ref v (case 'field [a 1] [b 2])))]))
+         (values
+          (lambda (x)
+            (let* ([x (<foo> copy* x [a 10])]
+                   [x (<foo> copy* x [a (+ a 1)])]
+                   [x (<foo> copy* x [a (+ a 2)])]
+                   [x (<foo> copy* x [a (+ a 3)])])
+              (+ (<foo> a x) (<foo> b x))))
+          (<foo> make [a 1] [b 2])))))
+   '(#2%values
+     (lambda (x)
+       (if (if (#2%vector? x)
+               (if (#3%fx= (#3%vector-length x) 3)
+                   (#2%eq? (#3%vector-ref x 0) '<foo>)
+                   #f)
+               #f)
+           (#2%void)
+           (#2%raise 'bad))
+       (let ([g (#3%vector-ref x 2)])
+         (#2%+ 16 g)))
+     '#(<foo> 1 2)))
 )
 
 (mat equality-of-refs
diff --git a/mats/patch-compile-0-t-f-f b/mats/patch-compile-0-t-f-f
index 164e49aa5..48afd5126 100644
--- a/mats/patch-compile-0-t-f-f
+++ b/mats/patch-compile-0-t-f-f
@@ -1,5 +1,5 @@
-*** output-compile-0-f-f-f-simple/errors-compile-0-f-f-f	Fri Dec 22 19:53:14 2023
---- output-compile-0-t-f-f-spi-rmg/errors-compile-0-t-f-f	Fri Dec 22 19:53:35 2023
+*** output-compile-0-f-f-f-simple/errors-compile-0-f-f-f	Sat Jan  6 12:58:31 2024
+--- output-compile-0-t-f-f-spi-rmg/errors-compile-0-t-f-f	Sat Jan  6 12:58:49 2024
 ***************
 *** 180,186 ****
   3.mo:Expected error in mat case-lambda: "incorrect number of arguments 2 to #<procedure foo>".
@@ -4085,28 +4085,40 @@
   cp0.mo:Expected error in mat expand-output: "expand-output: #<binary output port bytevector> is not a textual output port or #f".
   cp0.mo:Expected error in mat expand/optimize-output: "expand/optimize-output: #t is not a textual output port or #f".
 ***************
-*** 4281,4289 ****
-  5_6.mo:Expected error in mat vector-copy: "vector-copy: invalid start value -1".
-  5_6.mo:Expected error in mat vector-copy: "vector-copy: index 1 + count 3 is beyond the end of #(a b c)".
-  5_6.mo:Expected error in mat vector-copy: "vector-copy: invalid count -1".
+*** 4287,4301 ****
+  5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid start value -1".
+  5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: index 1 + count 3 is beyond the end of #(a b c)".
+  5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid count -1".
 ! 5_6.mo:Expected error in mat vector-set/copy: "incorrect argument count in call (vector-set/copy 1)".
 ! 5_6.mo:Expected error in mat vector-set/copy: "incorrect argument count in call (vector-set/copy (quote #(a b c)))".
 ! 5_6.mo:Expected error in mat vector-set/copy: "incorrect argument count in call (vector-set/copy (quote #(a b c)) 1)".
   5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: y is not a valid index for #(a b c)".
   5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: -1 is not a valid index for #(a b c)".
   5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: 3 is not a valid index for #(a b c)".
---- 4281,4289 ----
-  5_6.mo:Expected error in mat vector-copy: "vector-copy: invalid start value -1".
-  5_6.mo:Expected error in mat vector-copy: "vector-copy: index 1 + count 3 is beyond the end of #(a b c)".
-  5_6.mo:Expected error in mat vector-copy: "vector-copy: invalid count -1".
+! 5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect argument count in call (immutable-vector-set/copy 1)".
+! 5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect argument count in call (immutable-vector-set/copy (quote #(a b c)))".
+! 5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect argument count in call (immutable-vector-set/copy (quote #(a b c)) 1)".
+  5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: y is not a valid index for #(a b c)".
+  5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: -1 is not a valid index for #(a b c)".
+  5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: 3 is not a valid index for #(a b c)".
+--- 4287,4301 ----
+  5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid start value -1".
+  5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: index 1 + count 3 is beyond the end of #(a b c)".
+  5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid count -1".
 ! 5_6.mo:Expected error in mat vector-set/copy: "incorrect number of arguments 1 to #<procedure vector-set/copy>".
 ! 5_6.mo:Expected error in mat vector-set/copy: "incorrect number of arguments 1 to #<procedure vector-set/copy>".
 ! 5_6.mo:Expected error in mat vector-set/copy: "incorrect number of arguments 2 to #<procedure vector-set/copy>".
   5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: y is not a valid index for #(a b c)".
   5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: -1 is not a valid index for #(a b c)".
   5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: 3 is not a valid index for #(a b c)".
-***************
-*** 4367,4375 ****
+! 5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect number of arguments 1 to #<procedure immutable-vector-set/copy>".
+! 5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect number of arguments 1 to #<procedure immutable-vector-set/copy>".
+! 5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect number of arguments 2 to #<procedure immutable-vector-set/copy>".
+  5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: y is not a valid index for #(a b c)".
+  5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: -1 is not a valid index for #(a b c)".
+  5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: 3 is not a valid index for #(a b c)".
+***************
+*** 4383,4391 ****
   5_6.mo:Expected error in mat list->flvector: "list->flvector: (1.0 2.0 . 3.0) is not a proper list".
   5_6.mo:Expected error in mat list->flvector: "list->flvector: (1.0 2.0 3.0 2.0 3.0 2.0 ...) is circular".
   5_6.mo:Expected error in mat flvector->list: "flvector->list: (a b c) is not an flvector".
@@ -4116,7 +4128,7 @@
   5_6.mo:Expected error in mat vector-map: "vector-map: #() is not a procedure".
   5_6.mo:Expected error in mat vector-map: "vector-map: #() is not a procedure".
   5_6.mo:Expected error in mat vector-map: "vector-map: #() is not a procedure".
---- 4367,4375 ----
+--- 4383,4391 ----
   5_6.mo:Expected error in mat list->flvector: "list->flvector: (1.0 2.0 . 3.0) is not a proper list".
   5_6.mo:Expected error in mat list->flvector: "list->flvector: (1.0 2.0 3.0 2.0 3.0 2.0 ...) is circular".
   5_6.mo:Expected error in mat flvector->list: "flvector->list: (a b c) is not an flvector".
@@ -4127,7 +4139,7 @@
   5_6.mo:Expected error in mat vector-map: "vector-map: #() is not a procedure".
   5_6.mo:Expected error in mat vector-map: "vector-map: #() is not a procedure".
 ***************
-*** 4384,4392 ****
+*** 4400,4408 ****
   5_6.mo:Expected error in mat vector-map: "vector-map: lengths of input vectors #() and #(x) differ".
   5_6.mo:Expected error in mat vector-map: "vector-map: lengths of input vectors #(y) and #() differ".
   5_6.mo:Expected error in mat vector-map: "vector-map: lengths of input vectors #(y) and #() differ".
@@ -4137,7 +4149,7 @@
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: #() is not a procedure".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: #() is not a procedure".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: #() is not a procedure".
---- 4384,4392 ----
+--- 4400,4408 ----
   5_6.mo:Expected error in mat vector-map: "vector-map: lengths of input vectors #() and #(x) differ".
   5_6.mo:Expected error in mat vector-map: "vector-map: lengths of input vectors #(y) and #() differ".
   5_6.mo:Expected error in mat vector-map: "vector-map: lengths of input vectors #(y) and #() differ".
@@ -4148,7 +4160,7 @@
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: #() is not a procedure".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: #() is not a procedure".
 ***************
-*** 4401,4418 ****
+*** 4417,4434 ****
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: lengths of input vectors #() and #(x) differ".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: lengths of input vectors #(y) and #() differ".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: lengths of input vectors #(y) and #() differ".
@@ -4167,7 +4179,7 @@
   5_6.mo:Expected error in mat vector-sort!: "vector-sort!: 3 is not a mutable vector".
   5_6.mo:Expected error in mat vector-sort!: "vector-sort!: (1 2 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector-sort!: "vector-sort!: #(a b c) is not a procedure".
---- 4401,4418 ----
+--- 4417,4434 ----
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: lengths of input vectors #() and #(x) differ".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: lengths of input vectors #(y) and #() differ".
   5_6.mo:Expected error in mat vector-for-each: "vector-for-each: lengths of input vectors #(y) and #() differ".
@@ -4187,7 +4199,7 @@
   5_6.mo:Expected error in mat vector-sort!: "vector-sort!: (1 2 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector-sort!: "vector-sort!: #(a b c) is not a procedure".
 ***************
-*** 4421,4429 ****
+*** 4437,4445 ****
   5_6.mo:Expected error in mat vector->immutable-vector: "vector-set-fixnum!: #(1 2 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector->immutable-vector: "vector-fill!: #(1 2 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector->immutable-vector: "vector-sort!: #(1 2 3) is not a mutable vector".
@@ -4197,7 +4209,7 @@
   5_6.mo:Expected error in mat vector-cas!: "vector-cas!: 1 is not a mutable vector".
   5_6.mo:Expected error in mat vector-cas!: "vector-cas!: #(4 5 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector-cas!: "vector-cas!: #(4 5 3) is not a valid index for #(4 5 3)".
---- 4421,4429 ----
+--- 4437,4445 ----
   5_6.mo:Expected error in mat vector->immutable-vector: "vector-set-fixnum!: #(1 2 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector->immutable-vector: "vector-fill!: #(1 2 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector->immutable-vector: "vector-sort!: #(1 2 3) is not a mutable vector".
@@ -4208,7 +4220,7 @@
   5_6.mo:Expected error in mat vector-cas!: "vector-cas!: #(4 5 3) is not a mutable vector".
   5_6.mo:Expected error in mat vector-cas!: "vector-cas!: #(4 5 3) is not a valid index for #(4 5 3)".
 ***************
-*** 4503,4510 ****
+*** 4519,4526 ****
   5_7.mo:Expected error in mat putprop-getprop: "getprop: 3 is not a symbol".
   5_7.mo:Expected error in mat putprop-getprop: "putprop: "hi" is not a symbol".
   5_7.mo:Expected error in mat putprop-getprop: "property-list: (a b c) is not a symbol".
@@ -4217,7 +4229,7 @@
   5_8.mo:Expected error in mat box-cas!: "box-cas!: 1 is not a mutable box".
   5_8.mo:Expected error in mat box-cas!: "box-cas!: #&1 is not a mutable box".
   6.mo:Expected error in mat port-operations: "open-input-file: failed for nonexistent file: no such file or directory".
---- 4503,4510 ----
+--- 4519,4526 ----
   5_7.mo:Expected error in mat putprop-getprop: "getprop: 3 is not a symbol".
   5_7.mo:Expected error in mat putprop-getprop: "putprop: "hi" is not a symbol".
   5_7.mo:Expected error in mat putprop-getprop: "property-list: (a b c) is not a symbol".
@@ -4227,7 +4239,7 @@
   5_8.mo:Expected error in mat box-cas!: "box-cas!: #&1 is not a mutable box".
   6.mo:Expected error in mat port-operations: "open-input-file: failed for nonexistent file: no such file or directory".
 ***************
-*** 4542,4563 ****
+*** 4558,4579 ****
   6.mo:Expected error in mat port-operations: "clear-output-port: not permitted on closed port #<output port testfile.ss>".
   6.mo:Expected error in mat port-operations: "current-output-port: a is not a textual output port".
   6.mo:Expected error in mat port-operations: "current-input-port: a is not a textual input port".
@@ -4250,7 +4262,7 @@
   6.mo:Expected error in mat port-operations1: "open-input-output-file: furball is not a string".
   6.mo:Expected error in mat port-operations1: "open-input-output-file: failed for /probably/not/a/good/path: no such file or directory".
   6.mo:Expected error in mat port-operations1: "open-input-output-file: invalid option compressed".
---- 4542,4563 ----
+--- 4558,4579 ----
   6.mo:Expected error in mat port-operations: "clear-output-port: not permitted on closed port #<output port testfile.ss>".
   6.mo:Expected error in mat port-operations: "current-output-port: a is not a textual output port".
   6.mo:Expected error in mat port-operations: "current-input-port: a is not a textual input port".
@@ -4274,7 +4286,7 @@
   6.mo:Expected error in mat port-operations1: "open-input-output-file: failed for /probably/not/a/good/path: no such file or directory".
   6.mo:Expected error in mat port-operations1: "open-input-output-file: invalid option compressed".
 ***************
-*** 4566,4572 ****
+*** 4582,4588 ****
   6.mo:Expected error in mat port-operations1: "truncate-file: all-the-way is not a valid length".
   6.mo:Expected error in mat port-operations1: "truncate-file: #<input port testfile.ss> is not an output port".
   6.mo:Expected error in mat port-operations1: "truncate-file: animal-crackers is not an output port".
@@ -4282,7 +4294,7 @@
   6.mo:Expected error in mat port-operations1: "truncate-file: not permitted on closed port #<input/output port testfile.ss>".
   6.mo:Expected error in mat port-operations1: "get-output-string: #<input port string> is not a string output port".
   6.mo:Expected error in mat port-operations1: "get-output-string: #<output port testfile.ss> is not a string output port".
---- 4566,4572 ----
+--- 4582,4588 ----
   6.mo:Expected error in mat port-operations1: "truncate-file: all-the-way is not a valid length".
   6.mo:Expected error in mat port-operations1: "truncate-file: #<input port testfile.ss> is not an output port".
   6.mo:Expected error in mat port-operations1: "truncate-file: animal-crackers is not an output port".
@@ -4291,7 +4303,7 @@
   6.mo:Expected error in mat port-operations1: "get-output-string: #<input port string> is not a string output port".
   6.mo:Expected error in mat port-operations1: "get-output-string: #<output port testfile.ss> is not a string output port".
 ***************
-*** 4583,4590 ****
+*** 4599,4606 ****
   6.mo:Expected error in mat string-port-file-position: "file-position: -1 is not a valid position".
   6.mo:Expected error in mat fresh-line: "fresh-line: 3 is not a textual output port".
   6.mo:Expected error in mat fresh-line: "fresh-line: #<input port string> is not a textual output port".
@@ -4300,7 +4312,7 @@
   6.mo:Expected error in mat pretty-print: "pretty-format: 3 is not a symbol".
   6.mo:Expected error in mat pretty-print: "pretty-format: invalid format (bad 0 ... ... 0 format)".
   6.mo:Expected error in mat fasl: "separate-eval: Warning in fasl-write: fasl file content is compressed internally; compressing the file (#<binary output port testfile.ss>) is redundant and can slow fasl writing and reading significantly
---- 4583,4590 ----
+--- 4599,4606 ----
   6.mo:Expected error in mat string-port-file-position: "file-position: -1 is not a valid position".
   6.mo:Expected error in mat fresh-line: "fresh-line: 3 is not a textual output port".
   6.mo:Expected error in mat fresh-line: "fresh-line: #<input port string> is not a textual output port".
@@ -4310,7 +4322,7 @@
   6.mo:Expected error in mat pretty-print: "pretty-format: invalid format (bad 0 ... ... 0 format)".
   6.mo:Expected error in mat fasl: "separate-eval: Warning in fasl-write: fasl file content is compressed internally; compressing the file (#<binary output port testfile.ss>) is redundant and can slow fasl writing and reading significantly
 ***************
-*** 7214,7245 ****
+*** 7230,7261 ****
   io.mo:Expected error in mat port-operations: "put-u8: not permitted on closed port #<binary output port testfile.ss>".
   io.mo:Expected error in mat port-operations: "put-bytevector: not permitted on closed port #<binary output port testfile.ss>".
   io.mo:Expected error in mat port-operations: "flush-output-port: not permitted on closed port #<binary output port testfile.ss>".
@@ -4343,7 +4355,7 @@
   io.mo:Expected error in mat port-operations1: "open-file-input/output-port: failed for /probably/not/a/good/path: no such file or directory".
   io.mo:Expected error in mat port-operations1: "invalid file option uncompressed".
   io.mo:Expected error in mat port-operations1: "invalid file option truncate".
---- 7214,7245 ----
+--- 7230,7261 ----
   io.mo:Expected error in mat port-operations: "put-u8: not permitted on closed port #<binary output port testfile.ss>".
   io.mo:Expected error in mat port-operations: "put-bytevector: not permitted on closed port #<binary output port testfile.ss>".
   io.mo:Expected error in mat port-operations: "flush-output-port: not permitted on closed port #<binary output port testfile.ss>".
@@ -4377,7 +4389,7 @@
   io.mo:Expected error in mat port-operations1: "invalid file option uncompressed".
   io.mo:Expected error in mat port-operations1: "invalid file option truncate".
 ***************
-*** 7250,7256 ****
+*** 7266,7272 ****
   io.mo:Expected error in mat port-operations1: "set-port-length!: all-the-way is not a valid length".
   io.mo:Expected error in mat port-operations1: "truncate-port: #<binary input port testfile.ss> is not an output port".
   io.mo:Expected error in mat port-operations1: "truncate-port: animal-crackers is not an output port".
@@ -4385,7 +4397,7 @@
   io.mo:Expected error in mat port-operations1: "truncate-port: not permitted on closed port #<binary input/output port testfile.ss>".
   io.mo:Expected error in mat port-operations3: "file-port?: "not a port" is not a port".
   io.mo:Expected error in mat port-operations3: "port-file-descriptor: oops is not a port".
---- 7250,7256 ----
+--- 7266,7272 ----
   io.mo:Expected error in mat port-operations1: "set-port-length!: all-the-way is not a valid length".
   io.mo:Expected error in mat port-operations1: "truncate-port: #<binary input port testfile.ss> is not an output port".
   io.mo:Expected error in mat port-operations1: "truncate-port: animal-crackers is not an output port".
@@ -4394,7 +4406,7 @@
   io.mo:Expected error in mat port-operations3: "file-port?: "not a port" is not a port".
   io.mo:Expected error in mat port-operations3: "port-file-descriptor: oops is not a port".
 ***************
-*** 7448,7472 ****
+*** 7464,7488 ****
   io.mo:Expected error in mat low-level-port-operations: "set-binary-port-output-size!: #vu8(1 2 3) is not a valid size for #<binary output port bytevector>".
   io.mo:Expected error in mat low-level-port-operations: "set-binary-port-output-size!: -1 is not a valid size for #<binary output port bytevector>".
   io.mo:Expected error in mat low-level-port-operations: "set-binary-port-output-size!: 6 is not a valid size for #<binary output port bytevector>".
@@ -4420,7 +4432,7 @@
   io.mo:Expected error in mat make-codec-buffer: "make-codec-buffer: shoe is not a procedure".
   io.mo:Expected error in mat make-codec-buffer: "transcoded-port: make-codec-buffer #<procedure bad1> did not return a mutable bytevector of length at least four".
   io.mo:Expected error in mat make-codec-buffer: "transcoded-port: make-codec-buffer #<procedure bad2> did not return a mutable bytevector of length at least four".
---- 7448,7472 ----
+--- 7464,7488 ----
   io.mo:Expected error in mat low-level-port-operations: "set-binary-port-output-size!: #vu8(1 2 3) is not a valid size for #<binary output port bytevector>".
   io.mo:Expected error in mat low-level-port-operations: "set-binary-port-output-size!: -1 is not a valid size for #<binary output port bytevector>".
   io.mo:Expected error in mat low-level-port-operations: "set-binary-port-output-size!: 6 is not a valid size for #<binary output port bytevector>".
@@ -4447,7 +4459,7 @@
   io.mo:Expected error in mat make-codec-buffer: "transcoded-port: make-codec-buffer #<procedure bad1> did not return a mutable bytevector of length at least four".
   io.mo:Expected error in mat make-codec-buffer: "transcoded-port: make-codec-buffer #<procedure bad2> did not return a mutable bytevector of length at least four".
 ***************
-*** 7491,7506 ****
+*** 7507,7522 ****
   io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
   io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
   io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
@@ -4464,7 +4476,7 @@
   io.mo:Expected error in mat custom-binary-ports: "unget-u8: cannot unget 255 on #<binary input port foo>".
   io.mo:Expected error in mat custom-binary-ports: "put-u8: #<binary input port foo> is not a binary output port".
   io.mo:Expected error in mat custom-binary-ports: "port-length: #<binary input port foo> does not support operation".
---- 7491,7506 ----
+--- 7507,7522 ----
   io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
   io.mo:Expected error in mat compression: "port-file-compressed!: #<output port string> is not a file port".
   io.mo:Expected error in mat compression: "port-file-compressed!: cannot compress input/output port #<binary input/output port testfile.ss>".
@@ -4482,7 +4494,7 @@
   io.mo:Expected error in mat custom-binary-ports: "put-u8: #<binary input port foo> is not a binary output port".
   io.mo:Expected error in mat custom-binary-ports: "port-length: #<binary input port foo> does not support operation".
 ***************
-*** 7572,7593 ****
+*** 7588,7609 ****
   io.mo:Expected error in mat current-ports: "console-output-port: #<input port string> is not a textual output port".
   io.mo:Expected error in mat current-ports: "console-error-port: #<input port string> is not a textual output port".
   io.mo:Expected error in mat current-transcoder: "current-transcoder: #<output port string> is not a transcoder".
@@ -4505,7 +4517,7 @@
   io.mo:Expected error in mat utf-16-codec: "utf-16-codec: invalid endianness #f".
   io.mo:Expected error in mat to-fold-or-not-to-fold: "get-datum: invalid character name #\newLine at char 0 of #<input port string>".
   io.mo:Expected error in mat to-fold-or-not-to-fold: "get-datum: invalid character name #\newLine at char 15 of #<input port string>".
---- 7572,7593 ----
+--- 7588,7609 ----
   io.mo:Expected error in mat current-ports: "console-output-port: #<input port string> is not a textual output port".
   io.mo:Expected error in mat current-ports: "console-error-port: #<input port string> is not a textual output port".
   io.mo:Expected error in mat current-transcoder: "current-transcoder: #<output port string> is not a transcoder".
@@ -4529,7 +4541,7 @@
   io.mo:Expected error in mat to-fold-or-not-to-fold: "get-datum: invalid character name #\newLine at char 0 of #<input port string>".
   io.mo:Expected error in mat to-fold-or-not-to-fold: "get-datum: invalid character name #\newLine at char 15 of #<input port string>".
 ***************
-*** 7763,7769 ****
+*** 7779,7785 ****
   7.mo:Expected error in mat eval-when: "invalid syntax visit-x".
   7.mo:Expected error in mat eval-when: "invalid syntax revisit-x".
   7.mo:Expected error in mat compile-whole-program: "compile-whole-program: failed for nosuchfile.wpo: no such file or directory".
@@ -4537,7 +4549,7 @@
   7.mo:Expected error in mat compile-whole-program: "separate-eval: Exception in environment: attempt to import invisible library (testfile-wpo-lib)
   7.mo:Expected error in mat compile-whole-program: "separate-eval: Exception: library (testfile-wpo-a4) not found
   7.mo:Expected error in mat compile-whole-program: "separate-eval: Exception: library (testfile-wpo-c4) not found
---- 7763,7769 ----
+--- 7779,7785 ----
   7.mo:Expected error in mat eval-when: "invalid syntax visit-x".
   7.mo:Expected error in mat eval-when: "invalid syntax revisit-x".
   7.mo:Expected error in mat compile-whole-program: "compile-whole-program: failed for nosuchfile.wpo: no such file or directory".
@@ -4546,7 +4558,7 @@
   7.mo:Expected error in mat compile-whole-program: "separate-eval: Exception: library (testfile-wpo-a4) not found
   7.mo:Expected error in mat compile-whole-program: "separate-eval: Exception: library (testfile-wpo-c4) not found
 ***************
-*** 7829,7855 ****
+*** 7845,7871 ****
   7.mo:Expected error in mat concatenate-object-files: "separate-eval: Exception in verify-loadability: cannot find object file for library (testfile-cof1A)
   7.mo:Expected error in mat concatenate-object-files: "separate-eval: Exception in verify-loadability: cannot find object file for library (testfile-cof1B)
   7.mo:Expected error in mat top-level-value-functions: "top-level-bound?: "hello" is not a symbol".
@@ -4574,7 +4586,7 @@
   7.mo:Expected error in mat top-level-value-functions: "define-top-level-value: hello is not an environment".
   7.mo:Expected error in mat top-level-value-functions: "define-top-level-value: #<environment *scheme*> is not a symbol".
   7.mo:Expected error in mat top-level-value-functions: "variable i-am-not-bound-i-hope is not bound".
---- 7829,7855 ----
+--- 7845,7871 ----
   7.mo:Expected error in mat concatenate-object-files: "separate-eval: Exception in verify-loadability: cannot find object file for library (testfile-cof1A)
   7.mo:Expected error in mat concatenate-object-files: "separate-eval: Exception in verify-loadability: cannot find object file for library (testfile-cof1B)
   7.mo:Expected error in mat top-level-value-functions: "top-level-bound?: "hello" is not a symbol".
@@ -4603,7 +4615,7 @@
   7.mo:Expected error in mat top-level-value-functions: "define-top-level-value: #<environment *scheme*> is not a symbol".
   7.mo:Expected error in mat top-level-value-functions: "variable i-am-not-bound-i-hope is not bound".
 ***************
-*** 8182,8189 ****
+*** 8198,8205 ****
   record.mo:Expected error in mat r6rs-records-procedural: "incorrect number of arguments 1 to #<procedure>".
   record.mo:Expected error in mat r6rs-records-procedural: "incorrect number of arguments 1 to #<procedure>".
   record.mo:Expected error in mat r6rs-records-procedural: "incorrect number of arguments 3 to #<procedure>".
@@ -4612,7 +4624,7 @@
   record.mo:Expected error in mat r6rs-records-procedural: "make-record-constructor-descriptor: record constructor descriptor #<record constructor descriptor> is not for parent of record type #<record type grand-child>".
   record.mo:Expected error in mat r6rs-records-procedural: "make-record-type-descriptor: cannot extend sealed record type #<record type bar> as foo".
   record.mo:Expected error in mat r6rs-records-syntactic: "invalid syntax point".
---- 8182,8189 ----
+--- 8198,8205 ----
   record.mo:Expected error in mat r6rs-records-procedural: "incorrect number of arguments 1 to #<procedure>".
   record.mo:Expected error in mat r6rs-records-procedural: "incorrect number of arguments 1 to #<procedure>".
   record.mo:Expected error in mat r6rs-records-procedural: "incorrect number of arguments 3 to #<procedure>".
@@ -4622,7 +4634,7 @@
   record.mo:Expected error in mat r6rs-records-procedural: "make-record-type-descriptor: cannot extend sealed record type #<record type bar> as foo".
   record.mo:Expected error in mat r6rs-records-syntactic: "invalid syntax point".
 ***************
-*** 8273,8392 ****
+*** 8289,8408 ****
   hash.mo:Expected error in mat old-hash-table: "hash-table-for-each: ((a . b)) is not an eq hashtable".
   hash.mo:Expected error in mat old-hash-table: "incorrect number of arguments 2 to #<procedure>".
   hash.mo:Expected error in mat old-hash-table: "incorrect number of arguments 2 to #<procedure>".
@@ -4743,7 +4755,7 @@
   hash.mo:Expected error in mat hashtable-arguments: "hashtable-ephemeron?: (hash . table) is not a hashtable".
   hash.mo:Expected error in mat hash-return-value: "hashtable-ref: invalid hash-function #<procedure> return value "oops" for any".
   hash.mo:Expected error in mat hash-return-value: "hashtable-ref: invalid hash-function #<procedure> return value 3.5 for any".
---- 8273,8392 ----
+--- 8289,8408 ----
   hash.mo:Expected error in mat old-hash-table: "hash-table-for-each: ((a . b)) is not an eq hashtable".
   hash.mo:Expected error in mat old-hash-table: "incorrect number of arguments 2 to #<procedure>".
   hash.mo:Expected error in mat old-hash-table: "incorrect number of arguments 2 to #<procedure>".
@@ -4865,7 +4877,7 @@
   hash.mo:Expected error in mat hash-return-value: "hashtable-ref: invalid hash-function #<procedure> return value "oops" for any".
   hash.mo:Expected error in mat hash-return-value: "hashtable-ref: invalid hash-function #<procedure> return value 3.5 for any".
 ***************
-*** 8409,8537 ****
+*** 8425,8553 ****
   hash.mo:Expected error in mat hash-return-value: "hashtable-delete!: invalid hash-function #<procedure> return value "oops" for any".
   hash.mo:Expected error in mat hash-return-value: "hashtable-delete!: invalid hash-function #<procedure> return value 3.5 for any".
   hash.mo:Expected error in mat hash-return-value: "hashtable-delete!: invalid hash-function #<procedure> return value 1+2i for any".
@@ -4995,7 +5007,7 @@
   hash.mo:Expected error in mat eqv-hashtable-arguments: "make-ephemeron-eqv-hashtable: invalid size argument -1".
   hash.mo:Expected error in mat eqv-hashtable-arguments: "make-ephemeron-eqv-hashtable: invalid size argument #t".
   hash.mo:Expected error in mat eqv-hashtable-arguments: "make-ephemeron-eqv-hashtable: invalid size argument #f".
---- 8409,8537 ----
+--- 8425,8553 ----
   hash.mo:Expected error in mat hash-return-value: "hashtable-delete!: invalid hash-function #<procedure> return value "oops" for any".
   hash.mo:Expected error in mat hash-return-value: "hashtable-delete!: invalid hash-function #<procedure> return value 3.5 for any".
   hash.mo:Expected error in mat hash-return-value: "hashtable-delete!: invalid hash-function #<procedure> return value 1+2i for any".
@@ -5126,7 +5138,7 @@
   hash.mo:Expected error in mat eqv-hashtable-arguments: "make-ephemeron-eqv-hashtable: invalid size argument #t".
   hash.mo:Expected error in mat eqv-hashtable-arguments: "make-ephemeron-eqv-hashtable: invalid size argument #f".
 ***************
-*** 8539,8570 ****
+*** 8555,8586 ****
   hash.mo:Expected error in mat generic-hashtable: "hashtable-delete!: #<hashtable> is not mutable".
   hash.mo:Expected error in mat generic-hashtable: "hashtable-update!: #<hashtable> is not mutable".
   hash.mo:Expected error in mat generic-hashtable: "hashtable-update!: #<hashtable> is not mutable".
@@ -5159,7 +5171,7 @@
   hash.mo:Expected error in mat hash-functions: "string-ci-hash: hello is not a string".
   hash.mo:Expected error in mat fasl-other-hashtable: "fasl-write: invalid fasl object #<eqv hashtable>".
   hash.mo:Expected error in mat fasl-other-hashtable: "fasl-write: invalid fasl object #<hashtable>".
---- 8539,8570 ----
+--- 8555,8586 ----
   hash.mo:Expected error in mat generic-hashtable: "hashtable-delete!: #<hashtable> is not mutable".
   hash.mo:Expected error in mat generic-hashtable: "hashtable-update!: #<hashtable> is not mutable".
   hash.mo:Expected error in mat generic-hashtable: "hashtable-update!: #<hashtable> is not mutable".
@@ -5193,7 +5205,7 @@
   hash.mo:Expected error in mat fasl-other-hashtable: "fasl-write: invalid fasl object #<eqv hashtable>".
   hash.mo:Expected error in mat fasl-other-hashtable: "fasl-write: invalid fasl object #<hashtable>".
 ***************
-*** 8682,8689 ****
+*** 8698,8705 ****
   8.mo:Expected error in mat with-syntax: "invalid syntax a".
   8.mo:Expected error in mat with-syntax: "duplicate pattern variable x in (x x)".
   8.mo:Expected error in mat with-syntax: "duplicate pattern variable x in (x x)".
@@ -5202,7 +5214,7 @@
   8.mo:Expected error in mat generate-temporaries: "generate-temporaries: improper list structure (a b . c)".
   8.mo:Expected error in mat generate-temporaries: "generate-temporaries: cyclic list structure (a b c b c b ...)".
   8.mo:Expected error in mat syntax->list: "syntax->list: invalid argument #<syntax a>".
---- 8682,8689 ----
+--- 8698,8705 ----
   8.mo:Expected error in mat with-syntax: "invalid syntax a".
   8.mo:Expected error in mat with-syntax: "duplicate pattern variable x in (x x)".
   8.mo:Expected error in mat with-syntax: "duplicate pattern variable x in (x x)".
@@ -5212,7 +5224,7 @@
   8.mo:Expected error in mat generate-temporaries: "generate-temporaries: cyclic list structure (a b c b c b ...)".
   8.mo:Expected error in mat syntax->list: "syntax->list: invalid argument #<syntax a>".
 ***************
-*** 9300,9315 ****
+*** 9316,9331 ****
   8.mo:Expected error in mat rnrs-eval: "attempt to assign unbound identifier foo".
   8.mo:Expected error in mat rnrs-eval: "invalid definition in immutable environment (define cons (quote #<procedure vector>))".
   8.mo:Expected error in mat top-level-syntax-functions: "top-level-syntax: "hello" is not a symbol".
@@ -5229,7 +5241,7 @@
   8.mo:Expected error in mat top-level-syntax-functions: "define-top-level-syntax: hello is not an environment".
   8.mo:Expected error in mat top-level-syntax-functions: "define-top-level-syntax: #<environment *scheme*> is not a symbol".
   8.mo:Expected error in mat top-level-syntax-functions: "define-top-level-syntax: cannot modify immutable environment #<environment *scheme*>".
---- 9300,9315 ----
+--- 9316,9331 ----
   8.mo:Expected error in mat rnrs-eval: "attempt to assign unbound identifier foo".
   8.mo:Expected error in mat rnrs-eval: "invalid definition in immutable environment (define cons (quote #<procedure vector>))".
   8.mo:Expected error in mat top-level-syntax-functions: "top-level-syntax: "hello" is not a symbol".
@@ -5247,7 +5259,7 @@
   8.mo:Expected error in mat top-level-syntax-functions: "define-top-level-syntax: #<environment *scheme*> is not a symbol".
   8.mo:Expected error in mat top-level-syntax-functions: "define-top-level-syntax: cannot modify immutable environment #<environment *scheme*>".
 ***************
-*** 9408,9430 ****
+*** 9424,9446 ****
   fx.mo:Expected error in mat fx=?: "fx=?: (a) is not a fixnum".
   fx.mo:Expected error in mat fx=?: "fx=?: <int> is not a fixnum".
   fx.mo:Expected error in mat fx=?: "fx=?: <-int> is not a fixnum".
@@ -5271,7 +5283,7 @@
   fx.mo:Expected error in mat $fxu<: "incorrect number of arguments 1 to #<procedure $fxu<>".
   fx.mo:Expected error in mat $fxu<: "incorrect number of arguments 3 to #<procedure $fxu<>".
   fx.mo:Expected error in mat $fxu<: "$fxu<: <-int> is not a fixnum".
---- 9408,9430 ----
+--- 9424,9446 ----
   fx.mo:Expected error in mat fx=?: "fx=?: (a) is not a fixnum".
   fx.mo:Expected error in mat fx=?: "fx=?: <int> is not a fixnum".
   fx.mo:Expected error in mat fx=?: "fx=?: <-int> is not a fixnum".
@@ -5296,7 +5308,7 @@
   fx.mo:Expected error in mat $fxu<: "incorrect number of arguments 3 to #<procedure $fxu<>".
   fx.mo:Expected error in mat $fxu<: "$fxu<: <-int> is not a fixnum".
 ***************
-*** 9466,9478 ****
+*** 9482,9494 ****
   fx.mo:Expected error in mat fx-/wraparound: "fx-: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx-/wraparound: "fx-: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx*: "fx*: (a . b) is not a fixnum".
@@ -5310,7 +5322,7 @@
   fx.mo:Expected error in mat r6rs:fx*: "fx*: <int> is not a fixnum".
   fx.mo:Expected error in mat r6rs:fx*: "fx*: <-int> is not a fixnum".
   fx.mo:Expected error in mat r6rs:fx*: "fx*: #f is not a fixnum".
---- 9466,9478 ----
+--- 9482,9494 ----
   fx.mo:Expected error in mat fx-/wraparound: "fx-: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx-/wraparound: "fx-: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx*: "fx*: (a . b) is not a fixnum".
@@ -5325,7 +5337,7 @@
   fx.mo:Expected error in mat r6rs:fx*: "fx*: <-int> is not a fixnum".
   fx.mo:Expected error in mat r6rs:fx*: "fx*: #f is not a fixnum".
 ***************
-*** 9527,9539 ****
+*** 9543,9555 ****
   fx.mo:Expected error in mat fx1+: "fx1+: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx1+: "fx1+: <int> is not a fixnum".
   fx.mo:Expected error in mat fx1+: "fx1+: a is not a fixnum".
@@ -5339,7 +5351,7 @@
   fx.mo:Expected error in mat fxmax: "fxmax: a is not a fixnum".
   fx.mo:Expected error in mat fxmax: "fxmax: <int> is not a fixnum".
   fx.mo:Expected error in mat fxmax: "fxmax: <-int> is not a fixnum".
---- 9527,9539 ----
+--- 9543,9555 ----
   fx.mo:Expected error in mat fx1+: "fx1+: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx1+: "fx1+: <int> is not a fixnum".
   fx.mo:Expected error in mat fx1+: "fx1+: a is not a fixnum".
@@ -5354,7 +5366,7 @@
   fx.mo:Expected error in mat fxmax: "fxmax: <int> is not a fixnum".
   fx.mo:Expected error in mat fxmax: "fxmax: <-int> is not a fixnum".
 ***************
-*** 9639,9648 ****
+*** 9655,9664 ****
   fx.mo:Expected error in mat fxarithmetic-shift: "fxarithmetic-shift: fixnum overflow with arguments <int> and 10".
   fx.mo:Expected error in mat fxarithmetic-shift: "fxarithmetic-shift: fixnum overflow with arguments -4097 and <int>".
   fx.mo:Expected error in mat fxarithmetic-shift: "fxarithmetic-shift: fixnum overflow with arguments <-int> and 1".
@@ -5365,7 +5377,7 @@
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: 35.0 is not a fixnum".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: 5.0 is not a valid start index".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: 8.0 is not a valid end index".
---- 9639,9648 ----
+--- 9655,9664 ----
   fx.mo:Expected error in mat fxarithmetic-shift: "fxarithmetic-shift: fixnum overflow with arguments <int> and 10".
   fx.mo:Expected error in mat fxarithmetic-shift: "fxarithmetic-shift: fixnum overflow with arguments -4097 and <int>".
   fx.mo:Expected error in mat fxarithmetic-shift: "fxarithmetic-shift: fixnum overflow with arguments <-int> and 1".
@@ -5377,7 +5389,7 @@
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: 5.0 is not a valid start index".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: 8.0 is not a valid end index".
 ***************
-*** 9656,9689 ****
+*** 9672,9705 ****
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: <int> is not a valid end index".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: <int> is not a valid start index".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: <int> is not a valid end index".
@@ -5412,7 +5424,7 @@
   fx.mo:Expected error in mat fxif: "fxif: a is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: 3.4 is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: (a) is not a fixnum".
---- 9656,9689 ----
+--- 9672,9705 ----
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: <int> is not a valid end index".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: <int> is not a valid start index".
   fx.mo:Expected error in mat fxbit-field: "fxbit-field: <int> is not a valid end index".
@@ -5448,7 +5460,7 @@
   fx.mo:Expected error in mat fxif: "fxif: 3.4 is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: (a) is not a fixnum".
 ***************
-*** 9693,9736 ****
+*** 9709,9752 ****
   fx.mo:Expected error in mat fxif: "fxif: <-int> is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: <-int> is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: <-int> is not a fixnum".
@@ -5493,7 +5505,7 @@
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: 3.4 is not a fixnum".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: "3" is not a fixnum".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: <int> is not a fixnum".
---- 9693,9736 ----
+--- 9709,9752 ----
   fx.mo:Expected error in mat fxif: "fxif: <-int> is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: <-int> is not a fixnum".
   fx.mo:Expected error in mat fxif: "fxif: <-int> is not a fixnum".
@@ -5539,7 +5551,7 @@
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: "3" is not a fixnum".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: <int> is not a fixnum".
 ***************
-*** 9739,9749 ****
+*** 9755,9765 ****
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: invalid bit index -1".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: invalid bit index <int>".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: invalid bit index <int>".
@@ -5551,7 +5563,7 @@
   fx.mo:Expected error in mat fxcopy-bit-field: "fxcopy-bit-field: "3" is not a fixnum".
   fx.mo:Expected error in mat fxcopy-bit-field: "fxcopy-bit-field: 3.4 is not a valid start index".
   fx.mo:Expected error in mat fxcopy-bit-field: "fxcopy-bit-field: 3/4 is not a valid end index".
---- 9739,9749 ----
+--- 9755,9765 ----
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: invalid bit index -1".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: invalid bit index <int>".
   fx.mo:Expected error in mat fxcopy-bit: "fxcopy-bit: invalid bit index <int>".
@@ -5564,7 +5576,7 @@
   fx.mo:Expected error in mat fxcopy-bit-field: "fxcopy-bit-field: 3.4 is not a valid start index".
   fx.mo:Expected error in mat fxcopy-bit-field: "fxcopy-bit-field: 3/4 is not a valid end index".
 ***************
-*** 9803,9812 ****
+*** 9819,9828 ****
   fx.mo:Expected error in mat fxdiv0-and-mod0: "fxmod0: (a) is not a fixnum".
   fx.mo:Expected error in mat fxdiv0-and-mod0: "fxmod0: undefined for 0".
   fx.mo:Expected error in mat fxdiv0-and-mod0: "fxmod0: undefined for 0".
@@ -5575,7 +5587,7 @@
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: 1.0 is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: 2.0 is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: 3.0 is not a fixnum".
---- 9803,9812 ----
+--- 9819,9828 ----
   fx.mo:Expected error in mat fxdiv0-and-mod0: "fxmod0: (a) is not a fixnum".
   fx.mo:Expected error in mat fxdiv0-and-mod0: "fxmod0: undefined for 0".
   fx.mo:Expected error in mat fxdiv0-and-mod0: "fxmod0: undefined for 0".
@@ -5587,7 +5599,7 @@
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: 2.0 is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: 3.0 is not a fixnum".
 ***************
-*** 9822,9831 ****
+*** 9838,9847 ****
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: <-int> is not a fixnum".
@@ -5598,7 +5610,7 @@
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: 1.0 is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: 2.0 is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: 3.0 is not a fixnum".
---- 9822,9831 ----
+--- 9838,9847 ----
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx+/carry: "fx+/carry: <-int> is not a fixnum".
@@ -5610,7 +5622,7 @@
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: 2.0 is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: 3.0 is not a fixnum".
 ***************
-*** 9841,9850 ****
+*** 9857,9866 ****
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: <-int> is not a fixnum".
@@ -5621,7 +5633,7 @@
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: 1.0 is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: 2.0 is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: 3.0 is not a fixnum".
---- 9841,9850 ----
+--- 9857,9866 ----
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx-/carry: "fx-/carry: <-int> is not a fixnum".
@@ -5633,7 +5645,7 @@
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: 2.0 is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: 3.0 is not a fixnum".
 ***************
-*** 9860,9870 ****
+*** 9876,9886 ****
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: <-int> is not a fixnum".
@@ -5645,7 +5657,7 @@
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: a is not a fixnum".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid start index 0.0".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid end index 2.0".
---- 9860,9870 ----
+--- 9876,9886 ----
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: <-int> is not a fixnum".
   fx.mo:Expected error in mat fx*/carry: "fx*/carry: <-int> is not a fixnum".
@@ -5658,7 +5670,7 @@
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid start index 0.0".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid end index 2.0".
 ***************
-*** 9887,9896 ****
+*** 9903,9912 ****
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid end index <int>".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid end index <int>".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: count 1 is greater than difference between end index 5 and start index 5".
@@ -5669,7 +5681,7 @@
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: a is not a fixnum".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid start index 0.0".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid end index 2.0".
---- 9887,9896 ----
+--- 9903,9912 ----
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid end index <int>".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: invalid end index <int>".
   fx.mo:Expected error in mat fxrotate-bit-field: "fxrotate-bit-field: count 1 is greater than difference between end index 5 and start index 5".
@@ -5681,7 +5693,7 @@
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid start index 0.0".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid end index 2.0".
 ***************
-*** 9906,9923 ****
+*** 9922,9939 ****
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid end index <int>".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid end index <-int>".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: start index 7 is greater than end index 5".
@@ -5700,7 +5712,7 @@
   fl.mo:Expected error in mat fl=: "fl=: (a) is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: a is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: a is not a flonum".
---- 9906,9923 ----
+--- 9922,9939 ----
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid end index <int>".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: invalid end index <-int>".
   fx.mo:Expected error in mat fxreverse-bit-field: "fxreverse-bit-field: start index 7 is greater than end index 5".
@@ -5720,7 +5732,7 @@
   fl.mo:Expected error in mat fl=: "fl=: a is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: a is not a flonum".
 ***************
-*** 9925,9931 ****
+*** 9941,9947 ****
   fl.mo:Expected error in mat fl=: "fl=: 3 is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: 7/2 is not a flonum".
@@ -5728,7 +5740,7 @@
   fl.mo:Expected error in mat fl<: "fl<: (a) is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: a is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: a is not a flonum".
---- 9925,9931 ----
+--- 9941,9947 ----
   fl.mo:Expected error in mat fl=: "fl=: 3 is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl=: "fl=: 7/2 is not a flonum".
@@ -5737,7 +5749,7 @@
   fl.mo:Expected error in mat fl<: "fl<: a is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: a is not a flonum".
 ***************
-*** 9933,9939 ****
+*** 9949,9955 ****
   fl.mo:Expected error in mat fl<: "fl<: 3 is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: 7/2 is not a flonum".
@@ -5745,7 +5757,7 @@
   fl.mo:Expected error in mat fl>: "fl>: (a) is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: a is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: a is not a flonum".
---- 9933,9939 ----
+--- 9949,9955 ----
   fl.mo:Expected error in mat fl<: "fl<: 3 is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl<: "fl<: 7/2 is not a flonum".
@@ -5754,7 +5766,7 @@
   fl.mo:Expected error in mat fl>: "fl>: a is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: a is not a flonum".
 ***************
-*** 9941,9947 ****
+*** 9957,9963 ****
   fl.mo:Expected error in mat fl>: "fl>: 3 is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: 7/2 is not a flonum".
@@ -5762,7 +5774,7 @@
   fl.mo:Expected error in mat fl<=: "fl<=: (a) is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: a is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: a is not a flonum".
---- 9941,9947 ----
+--- 9957,9963 ----
   fl.mo:Expected error in mat fl>: "fl>: 3 is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl>: "fl>: 7/2 is not a flonum".
@@ -5771,7 +5783,7 @@
   fl.mo:Expected error in mat fl<=: "fl<=: a is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: a is not a flonum".
 ***************
-*** 9949,9955 ****
+*** 9965,9971 ****
   fl.mo:Expected error in mat fl<=: "fl<=: 3 is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: 7/2 is not a flonum".
@@ -5779,7 +5791,7 @@
   fl.mo:Expected error in mat fl>=: "fl>=: (a) is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: a is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: a is not a flonum".
---- 9949,9955 ----
+--- 9965,9971 ----
   fl.mo:Expected error in mat fl<=: "fl<=: 3 is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl<=: "fl<=: 7/2 is not a flonum".
@@ -5788,7 +5800,7 @@
   fl.mo:Expected error in mat fl>=: "fl>=: a is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: a is not a flonum".
 ***************
-*** 9957,9996 ****
+*** 9973,10012 ****
   fl.mo:Expected error in mat fl>=: "fl>=: 3 is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: 7/2 is not a flonum".
@@ -5829,7 +5841,7 @@
   fl.mo:Expected error in mat fl>=?: "fl>=?: a is not a flonum".
   fl.mo:Expected error in mat fl>=?: "fl>=?: a is not a flonum".
   fl.mo:Expected error in mat fl>=?: "fl>=?: 3 is not a flonum".
---- 9957,9996 ----
+--- 9973,10012 ----
   fl.mo:Expected error in mat fl>=: "fl>=: 3 is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: 7/2 is not a flonum".
   fl.mo:Expected error in mat fl>=: "fl>=: 7/2 is not a flonum".
@@ -5871,7 +5883,7 @@
   fl.mo:Expected error in mat fl>=?: "fl>=?: a is not a flonum".
   fl.mo:Expected error in mat fl>=?: "fl>=?: 3 is not a flonum".
 ***************
-*** 10000,10006 ****
+*** 10016,10022 ****
   fl.mo:Expected error in mat fl+: "fl+: (a . b) is not a flonum".
   fl.mo:Expected error in mat fl+: "fl+: 1 is not a flonum".
   fl.mo:Expected error in mat fl+: "fl+: 2/3 is not a flonum".
@@ -5879,7 +5891,7 @@
   fl.mo:Expected error in mat fl-: "fl-: (a . b) is not a flonum".
   fl.mo:Expected error in mat fl-: "fl-: 1 is not a flonum".
   fl.mo:Expected error in mat fl-: "fl-: a is not a flonum".
---- 10000,10006 ----
+--- 10016,10022 ----
   fl.mo:Expected error in mat fl+: "fl+: (a . b) is not a flonum".
   fl.mo:Expected error in mat fl+: "fl+: 1 is not a flonum".
   fl.mo:Expected error in mat fl+: "fl+: 2/3 is not a flonum".
@@ -5888,7 +5900,7 @@
   fl.mo:Expected error in mat fl-: "fl-: 1 is not a flonum".
   fl.mo:Expected error in mat fl-: "fl-: a is not a flonum".
 ***************
-*** 10010,10099 ****
+*** 10026,10115 ****
   fl.mo:Expected error in mat fl*: "fl*: (a . b) is not a flonum".
   fl.mo:Expected error in mat fl*: "fl*: 1 is not a flonum".
   fl.mo:Expected error in mat fl*: "fl*: 2/3 is not a flonum".
@@ -5979,7 +5991,7 @@
   fl.mo:Expected error in mat flsingle: "flsingle: a is not a flonum".
   fl.mo:Expected error in mat flsingle: "flsingle: 3 is not a flonum".
   fl.mo:Expected error in mat flsingle: "flsingle: 2.0+1.0i is not a flonum".
---- 10010,10099 ----
+--- 10026,10115 ----
   fl.mo:Expected error in mat fl*: "fl*: (a . b) is not a flonum".
   fl.mo:Expected error in mat fl*: "fl*: 1 is not a flonum".
   fl.mo:Expected error in mat fl*: "fl*: 2/3 is not a flonum".
@@ -6071,7 +6083,7 @@
   fl.mo:Expected error in mat flsingle: "flsingle: 3 is not a flonum".
   fl.mo:Expected error in mat flsingle: "flsingle: 2.0+1.0i is not a flonum".
 ***************
-*** 10112,10147 ****
+*** 10128,10163 ****
   fl.mo:Expected error in mat flinfinite?: "flinfinite?: 3 is not a flonum".
   fl.mo:Expected error in mat flinfinite?: "flinfinite?: 3/4 is not a flonum".
   fl.mo:Expected error in mat flinfinite?: "flinfinite?: hi is not a flonum".
@@ -6108,7 +6120,7 @@
   fl.mo:Expected error in mat fleven?: "fleven?: a is not a flonum".
   fl.mo:Expected error in mat fleven?: "fleven?: 3 is not a flonum".
   fl.mo:Expected error in mat fleven?: "fleven?: 3.2 is not an integer".
---- 10112,10147 ----
+--- 10128,10163 ----
   fl.mo:Expected error in mat flinfinite?: "flinfinite?: 3 is not a flonum".
   fl.mo:Expected error in mat flinfinite?: "flinfinite?: 3/4 is not a flonum".
   fl.mo:Expected error in mat flinfinite?: "flinfinite?: hi is not a flonum".
@@ -6146,7 +6158,7 @@
   fl.mo:Expected error in mat fleven?: "fleven?: 3 is not a flonum".
   fl.mo:Expected error in mat fleven?: "fleven?: 3.2 is not an integer".
 ***************
-*** 10149,10156 ****
+*** 10165,10172 ****
   fl.mo:Expected error in mat fleven?: "fleven?: 1+1i is not a flonum".
   fl.mo:Expected error in mat fleven?: "fleven?: +inf.0 is not an integer".
   fl.mo:Expected error in mat fleven?: "fleven?: +nan.0 is not an integer".
@@ -6155,7 +6167,7 @@
   fl.mo:Expected error in mat flodd?: "flodd?: a is not a flonum".
   fl.mo:Expected error in mat flodd?: "flodd?: 3 is not a flonum".
   fl.mo:Expected error in mat flodd?: "flodd?: 3.2 is not an integer".
---- 10149,10156 ----
+--- 10165,10172 ----
   fl.mo:Expected error in mat fleven?: "fleven?: 1+1i is not a flonum".
   fl.mo:Expected error in mat fleven?: "fleven?: +inf.0 is not an integer".
   fl.mo:Expected error in mat fleven?: "fleven?: +nan.0 is not an integer".
@@ -6165,7 +6177,7 @@
   fl.mo:Expected error in mat flodd?: "flodd?: 3 is not a flonum".
   fl.mo:Expected error in mat flodd?: "flodd?: 3.2 is not an integer".
 ***************
-*** 10158,10164 ****
+*** 10174,10180 ****
   fl.mo:Expected error in mat flodd?: "flodd?: 3+1i is not a flonum".
   fl.mo:Expected error in mat flodd?: "flodd?: +inf.0 is not an integer".
   fl.mo:Expected error in mat flodd?: "flodd?: +nan.0 is not an integer".
@@ -6173,7 +6185,7 @@
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
---- 10158,10164 ----
+--- 10174,10180 ----
   fl.mo:Expected error in mat flodd?: "flodd?: 3+1i is not a flonum".
   fl.mo:Expected error in mat flodd?: "flodd?: +inf.0 is not an integer".
   fl.mo:Expected error in mat flodd?: "flodd?: +nan.0 is not an integer".
@@ -6182,7 +6194,7 @@
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
 ***************
-*** 10166,10172 ****
+*** 10182,10188 ****
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: 0.0+1.0i is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: 0+1i is not a flonum".
@@ -6190,7 +6202,7 @@
   fl.mo:Expected error in mat flmax: "flmax: a is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: a is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: 3 is not a flonum".
---- 10166,10172 ----
+--- 10182,10188 ----
   fl.mo:Expected error in mat flmin: "flmin: a is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: 0.0+1.0i is not a flonum".
   fl.mo:Expected error in mat flmin: "flmin: 0+1i is not a flonum".
@@ -6199,7 +6211,7 @@
   fl.mo:Expected error in mat flmax: "flmax: a is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: 3 is not a flonum".
 ***************
-*** 10174,10187 ****
+*** 10190,10203 ****
   fl.mo:Expected error in mat flmax: "flmax: a is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: 0.0+1.0i is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: 0+1i is not a flonum".
@@ -6214,7 +6226,7 @@
   fl.mo:Expected error in mat fldenominator: "fldenominator: a is not a flonum".
   fl.mo:Expected error in mat fldenominator: "fldenominator: 3 is not a flonum".
   fl.mo:Expected error in mat fldenominator: "fldenominator: 0+1i is not a flonum".
---- 10174,10187 ----
+--- 10190,10203 ----
   fl.mo:Expected error in mat flmax: "flmax: a is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: 0.0+1.0i is not a flonum".
   fl.mo:Expected error in mat flmax: "flmax: 0+1i is not a flonum".
@@ -6230,7 +6242,7 @@
   fl.mo:Expected error in mat fldenominator: "fldenominator: 3 is not a flonum".
   fl.mo:Expected error in mat fldenominator: "fldenominator: 0+1i is not a flonum".
 ***************
-*** 10227,10233 ****
+*** 10243,10249 ****
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
@@ -6238,7 +6250,7 @@
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
---- 10227,10233 ----
+--- 10243,10249 ----
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
@@ -6247,7 +6259,7 @@
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
   cfl.mo:Expected error in mat cfl-: "cfl-: a is not a cflonum".
 ***************
-*** 10237,10250 ****
+*** 10253,10266 ****
   cfl.mo:Expected error in mat cfl/: "cfl/: a is not a cflonum".
   cfl.mo:Expected error in mat cfl/: "cfl/: a is not a cflonum".
   cfl.mo:Expected error in mat cfl/: "cfl/: a is not a cflonum".
@@ -6262,7 +6274,7 @@
   foreign.mo:Expected error in mat load-shared-object: "load-shared-object: invalid path 3".
   foreign.mo:Expected error in mat foreign-procedure: "foreign-procedure: no entry for "i do not exist"".
   foreign.mo:Expected error in mat foreign-procedure: "foreign-procedure: no entry for "i do not exist"".
---- 10237,10250 ----
+--- 10253,10266 ----
   cfl.mo:Expected error in mat cfl/: "cfl/: a is not a cflonum".
   cfl.mo:Expected error in mat cfl/: "cfl/: a is not a cflonum".
   cfl.mo:Expected error in mat cfl/: "cfl/: a is not a cflonum".
@@ -6278,7 +6290,7 @@
   foreign.mo:Expected error in mat foreign-procedure: "foreign-procedure: no entry for "i do not exist"".
   foreign.mo:Expected error in mat foreign-procedure: "foreign-procedure: no entry for "i do not exist"".
 ***************
-*** 10279,10286 ****
+*** 10295,10302 ****
   foreign.mo:Expected error in mat foreign-procedure: "id: invalid foreign-procedure argument foo".
   foreign.mo:Expected error in mat foreign-procedure: "foreign-procedure: invalid foreign procedure handle abcde".
   foreign.mo:Expected error in mat foreign-procedure: "float_id: invalid foreign-procedure argument 0".
@@ -6287,7 +6299,7 @@
   foreign.mo:Expected error in mat foreign-sizeof: "foreign-sizeof: invalid foreign type specifier i-am-not-a-type".
   foreign.mo:Expected error in mat foreign-sizeof: "foreign-sizeof: invalid foreign type specifier 1".
   foreign.mo:Expected error in mat foreign-bytevectors: "u8*->u8*: invalid foreign-procedure argument "hello"".
---- 10279,10286 ----
+--- 10295,10302 ----
   foreign.mo:Expected error in mat foreign-procedure: "id: invalid foreign-procedure argument foo".
   foreign.mo:Expected error in mat foreign-procedure: "foreign-procedure: invalid foreign procedure handle abcde".
   foreign.mo:Expected error in mat foreign-procedure: "float_id: invalid foreign-procedure argument 0".
@@ -6297,7 +6309,7 @@
   foreign.mo:Expected error in mat foreign-sizeof: "foreign-sizeof: invalid foreign type specifier 1".
   foreign.mo:Expected error in mat foreign-bytevectors: "u8*->u8*: invalid foreign-procedure argument "hello"".
 ***************
-*** 10787,10799 ****
+*** 10803,10815 ****
   unix.mo:Expected error in mat file-operations: "file-access-time: failed for "testlink": no such file or directory".
   unix.mo:Expected error in mat file-operations: "file-change-time: failed for "testlink": no such file or directory".
   unix.mo:Expected error in mat file-operations: "file-modification-time: failed for "testlink": no such file or directory".
@@ -6311,7 +6323,7 @@
   windows.mo:Expected error in mat registry: "get-registry: pooh is not a string".
   windows.mo:Expected error in mat registry: "put-registry!: 3 is not a string".
   windows.mo:Expected error in mat registry: "put-registry!: 3 is not a string".
---- 10787,10799 ----
+--- 10803,10815 ----
   unix.mo:Expected error in mat file-operations: "file-access-time: failed for "testlink": no such file or directory".
   unix.mo:Expected error in mat file-operations: "file-change-time: failed for "testlink": no such file or directory".
   unix.mo:Expected error in mat file-operations: "file-modification-time: failed for "testlink": no such file or directory".
@@ -6326,7 +6338,7 @@
   windows.mo:Expected error in mat registry: "put-registry!: 3 is not a string".
   windows.mo:Expected error in mat registry: "put-registry!: 3 is not a string".
 ***************
-*** 10821,10892 ****
+*** 10837,10908 ****
   ieee.mo:Expected error in mat flonum->fixnum: "flonum->fixnum: result for -inf.0 would be outside of fixnum range".
   ieee.mo:Expected error in mat flonum->fixnum: "flonum->fixnum: result for +nan.0 would be outside of fixnum range".
   ieee.mo:Expected error in mat fllp: "fllp: 3 is not a flonum".
@@ -6399,7 +6411,7 @@
   date.mo:Expected error in mat time: "time>=?: 3 is not a time record".
   date.mo:Expected error in mat time: "time>=?: #<procedure car> is not a time record".
   date.mo:Expected error in mat time: "time>=?: types of <time> and <time> differ".
---- 10821,10892 ----
+--- 10837,10908 ----
   ieee.mo:Expected error in mat flonum->fixnum: "flonum->fixnum: result for -inf.0 would be outside of fixnum range".
   ieee.mo:Expected error in mat flonum->fixnum: "flonum->fixnum: result for +nan.0 would be outside of fixnum range".
   ieee.mo:Expected error in mat fllp: "fllp: 3 is not a flonum".
@@ -6473,7 +6485,7 @@
   date.mo:Expected error in mat time: "time>=?: #<procedure car> is not a time record".
   date.mo:Expected error in mat time: "time>=?: types of <time> and <time> differ".
 ***************
-*** 10894,10907 ****
+*** 10910,10923 ****
   date.mo:Expected error in mat time: "add-duration: <time> does not have type time-duration".
   date.mo:Expected error in mat time: "subtract-duration: <time> does not have type time-duration".
   date.mo:Expected error in mat time: "copy-time: <date> is not a time record".
@@ -6488,7 +6500,7 @@
   date.mo:Expected error in mat date: "make-date: invalid nanosecond -1".
   date.mo:Expected error in mat date: "make-date: invalid nanosecond <int>".
   date.mo:Expected error in mat date: "make-date: invalid nanosecond zero".
---- 10894,10907 ----
+--- 10910,10923 ----
   date.mo:Expected error in mat time: "add-duration: <time> does not have type time-duration".
   date.mo:Expected error in mat time: "subtract-duration: <time> does not have type time-duration".
   date.mo:Expected error in mat time: "copy-time: <date> is not a time record".
@@ -6504,7 +6516,7 @@
   date.mo:Expected error in mat date: "make-date: invalid nanosecond <int>".
   date.mo:Expected error in mat date: "make-date: invalid nanosecond zero".
 ***************
-*** 10927,10987 ****
+*** 10943,11003 ****
   date.mo:Expected error in mat date: "make-date: invalid time-zone offset 90000".
   date.mo:Expected error in mat date: "make-date: invalid time-zone offset est".
   date.mo:Expected error in mat date: "make-date: invalid time-zone offset "est"".
@@ -6566,7 +6578,7 @@
   date.mo:Expected error in mat date: "current-date: invalid time-zone offset -90000".
   date.mo:Expected error in mat date: "current-date: invalid time-zone offset 90000".
   date.mo:Expected error in mat conversions/sleep: "date->time-utc: <time> is not a date record".
---- 10927,10987 ----
+--- 10943,11003 ----
   date.mo:Expected error in mat date: "make-date: invalid time-zone offset 90000".
   date.mo:Expected error in mat date: "make-date: invalid time-zone offset est".
   date.mo:Expected error in mat date: "make-date: invalid time-zone offset "est"".
diff --git a/mats/record.ms b/mats/record.ms
index bb7708698..6dbc1bc6c 100644
--- a/mats/record.ms
+++ b/mats/record.ms
@@ -9008,9 +9008,10 @@
                        (new q x)))))))
            (make-foo 3))))
     `(let ([ctr 0])
-       (letrec ([g0 (lambda (new) (lambda (q) (new q (begin (set! ctr (#2%+ 1 xtr)) ctr))))])
+       (letrec ([g0 (lambda (new) (lambda (q) (set! ctr (#2%+ 1 xtr)) (new q ctr)))])
          (#3%$value (#3%$make-record-constructor-descriptor ',record-type-descriptor?  #f g0 'define-record-type))
-         (#3%$record ',record-type-descriptor? 3 (begin (set! ctr (#2%+ 1 xtr)) ctr)))))
+         (set! ctr (#2%+ 1 xtr))
+         (#3%$record ',record-type-descriptor? 3 ctr))))
   (equivalent-expansion?
     (parameterize ([optimize-level 3] [enable-cp0 #t] [#%$suppress-primitive-inlining #f])
       (expand/optimize
@@ -9027,9 +9028,10 @@
                        (new q x)))))))
            (make-foo 3))))
     `(let ([ctr 0])
-       (letrec ([g0 (lambda (new) (lambda (q) (new q (begin (set! ctr (#3%+ 1 xtr)) ctr))))])
+       (letrec ([g0 (lambda (new) (lambda (q) (set! ctr (#3%+ 1 xtr)) (new q ctr)))])
          (#3%$value (#3%$make-record-constructor-descriptor ',record-type-descriptor?  #f g0 'define-record-type))
-         (#3%$record ',record-type-descriptor? 3 (begin (set! ctr (#3%+ 1 xtr)) ctr)))))
+         (set! ctr (#3%+ 1 xtr))
+         (#3%$record ',record-type-descriptor? 3 ctr))))
   (error? ; invalid uid
     (let ()
       (define useless
diff --git a/mats/root-experr-compile-0-f-f-f b/mats/root-experr-compile-0-f-f-f
index ec94708ff..b8df4f0b1 100644
--- a/mats/root-experr-compile-0-f-f-f
+++ b/mats/root-experr-compile-0-f-f-f
@@ -4281,16 +4281,34 @@ cp0.mo:Expected error in mat expand/optimize-output: "expand/optimize-output: #<
 5_6.mo:Expected error in mat vector-copy: "vector-copy: invalid start value -1".
 5_6.mo:Expected error in mat vector-copy: "vector-copy: index 1 + count 3 is beyond the end of #(a b c)".
 5_6.mo:Expected error in mat vector-copy: "vector-copy: invalid count -1".
+5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: (a b c) is not a vector".
+5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid start value x".
+5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid count x".
+5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid start value -1".
+5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: index 1 + count 3 is beyond the end of #(a b c)".
+5_6.mo:Expected error in mat immutable-vector-copy: "immutable-vector-copy: invalid count -1".
 5_6.mo:Expected error in mat vector-set/copy: "incorrect argument count in call (vector-set/copy 1)".
 5_6.mo:Expected error in mat vector-set/copy: "incorrect argument count in call (vector-set/copy (quote #(a b c)))".
 5_6.mo:Expected error in mat vector-set/copy: "incorrect argument count in call (vector-set/copy (quote #(a b c)) 1)".
 5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: y is not a valid index for #(a b c)".
 5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: -1 is not a valid index for #(a b c)".
 5_6.mo:Expected error in mat vector-set/copy: "vector-set/copy: 3 is not a valid index for #(a b c)".
+5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect argument count in call (immutable-vector-set/copy 1)".
+5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect argument count in call (immutable-vector-set/copy (quote #(a b c)))".
+5_6.mo:Expected error in mat immutable-vector-set/copy: "incorrect argument count in call (immutable-vector-set/copy (quote #(a b c)) 1)".
+5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: y is not a valid index for #(a b c)".
+5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: -1 is not a valid index for #(a b c)".
+5_6.mo:Expected error in mat immutable-vector-set/copy: "immutable-vector-set/copy: 3 is not a valid index for #(a b c)".
 5_6.mo:Expected error in mat vector-append: "vector-append: 1 is not a vector".
 5_6.mo:Expected error in mat vector-append: "vector-append: x is not a vector".
 5_6.mo:Expected error in mat vector-append: "vector-append: x is not a vector".
 5_6.mo:Expected error in mat vector-append: "vector-append: x is not a vector".
+5_6.mo:Expected error in mat vector-append: "make-vector: -1 is not a valid vector length".
+5_6.mo:Expected error in mat immutable-vector-append: "immutable-vector-append: 1 is not a vector".
+5_6.mo:Expected error in mat immutable-vector-append: "immutable-vector-append: x is not a vector".
+5_6.mo:Expected error in mat immutable-vector-append: "immutable-vector-append: x is not a vector".
+5_6.mo:Expected error in mat immutable-vector-append: "immutable-vector-append: x is not a vector".
+5_6.mo:Expected error in mat immutable-vector-append: "make-vector: -1 is not a valid vector length".
 5_6.mo:Expected error in mat vector-fill!: "vector-fill!: #vfx() is not a mutable vector".
 5_6.mo:Expected error in mat list->vector: "list->vector: #(a b c) is not a proper list".
 5_6.mo:Expected error in mat list->vector: "list->vector: (#\a #\b . #\c) is not a proper list".
diff --git a/release_notes/release_notes.stex b/release_notes/release_notes.stex
index 4168a3620..6571ff70b 100644
--- a/release_notes/release_notes.stex
+++ b/release_notes/release_notes.stex
@@ -469,18 +469,24 @@ stencil-vector-mask-width
 \subsection{New vector functions (9.9.9)}
 
 New and extended (in the case of \scheme{vector-copy}) vector functions
-support creating a vector from the content of others:
+support creating a vector from the content of others and creating immutable
+vectors:
 
 \schemedisplay
 vector-copy
 vector-append
 vector-set/copy
+immutable-vector
+immutable-vector-copy
+immutable-vector-append
+immutable-vector-set/copy
 \endschemedisplay
 
-Although these functions could be implemented with
-\scheme{make-vector} and \scheme{vector-set!}, the new versions avoid
-redundant initialization and write barriers.
-
+Although the mutable-vector variants of these functions could be
+implemented with \scheme{make-vector} and \scheme{vector-set!}, the
+new versions can avoid redundant initialization and write barriers.
+The immutable-vector functions similarly can avoid allocating an
+intermediate mutable vector.
 
 \subsection{New symbol functions (9.9.9)}
 
diff --git a/s/5_6.ss b/s/5_6.ss
index f4b6ceecd..2511501ba 100644
--- a/s/5_6.ss
+++ b/s/5_6.ss
@@ -44,65 +44,109 @@
        (loop (fx- i 2))]
       [(fx= i 0) (vector-set! v2 (fx+ i delta) (vector-ref v1 i))])))
 
-(set-who! vector-copy
-  (case-lambda
-   [(v)
-    (unless (vector? v)
-      ($oops who "~s is not a vector" v))
-    (#3%vector-copy v 0 (vector-length v))]
-   [(v start len)
+(let ()
+  (define (not-a-vector who v)
+    ($oops who "~s is not a vector" v))
+  
+  (define (check-vector-range who v start len)
     (unless (vector? v)
-      ($oops who "~s is not a vector" v))
+      (not-a-vector who v))
     (unless (and (fixnum? start) (fx>= start 0))
       ($oops who "invalid start value ~s" start))
     (unless (and (fixnum? len) (fx>= len 0))
       ($oops who "invalid count ~s" len))
     (unless (fx<= len (fx- (vector-length v) start)) ; avoid overflow
-      ($oops who "index ~s + count ~s is beyond the end of ~s" start len v))
-    (#3%vector-copy v start len)]))
+      ($oops who "index ~s + count ~s is beyond the end of ~s" start len v)))
+
+  (define (append-vectors who vs)
+    (let ([len (let loop ([vs vs])
+                 (cond
+                   [(null? vs) 0]
+                   [else
+                    (let ([v (car vs)])
+                      (unless (vector? v) (not-a-vector who v))
+                      (fx+ (vector-length v) (loop (cdr vs))))]))])
+      (let ([dest (make-vector len)])
+        (let loop ([vs vs] [i 0])
+          (cond
+            [(null? vs) dest]
+            [else
+             (let* ([v (car vs)]
+                    [len (vector-length v)])
+               ($vector-copy! v dest len i)
+               (loop (cdr vs) (fx+ i len)))])))))
+    
+  (set-who! vector-copy
+    (case-lambda
+      [(v)
+       (unless (vector? v) (not-a-vector who v))
+       (#3%vector-copy v 0 (vector-length v))]
+      [(v start len)
+       (check-vector-range who v start len)
+       (#3%vector-copy v start len)]))
 
-(set-who! vector-append
-  (let ([not-a-vector
-         (lambda (v)
-           ($oops who "~s is not a vector" v))])
+  (set-who! immutable-vector-copy
+    (case-lambda
+      [(v)
+       (unless (vector? v) (not-a-vector who v))
+       (#3%immutable-vector-copy v)]
+      [(v start len)
+       (check-vector-range who v start len)
+       (#3%immutable-vector-copy v start len)]))
+
+  (set-who! vector-append
     (case-lambda
       [(v)
-       (unless (vector? v) (not-a-vector v))
+       (unless (vector? v) (not-a-vector who v))
        (vector-copy v)]
       [(v1 v2)
-       (unless (vector? v1) (not-a-vector v1))
-       (unless (vector? v2) (not-a-vector v2))
+       (unless (vector? v1) (not-a-vector who v1))
+       (unless (vector? v2) (not-a-vector who v2))
        (#3%vector-append v1 v2)]
       [(v1 v2 v3)
-       (unless (vector? v1) (not-a-vector v1))
-       (unless (vector? v2) (not-a-vector v2))
-       (unless (vector? v3) (not-a-vector v3))
+       (unless (vector? v1) (not-a-vector who v1))
+       (unless (vector? v2) (not-a-vector who v2))
+       (unless (vector? v3) (not-a-vector who v3))
        (#3%vector-append v1 v2 v3)]
       [vs
-       (let ([len (let loop ([vs vs])
-                    (cond
-                      [(null? vs) 0]
-                      [else
-                       (let ([v (car vs)])
-                         (unless (vector? v) (not-a-vector v))
-                         (fx+ (vector-length v) (loop (cdr vs))))]))])
-         (let ([dest (make-vector len)])
-           (let loop ([vs vs] [i 0])
-             (cond
-               [(null? vs) dest]
-               [else
-                (let* ([v (car vs)]
-                       [len (vector-length v)])
-                  ($vector-copy! v dest len i)
-                  (loop (cdr vs) (fx+ i len)))]))))])))
-
-(set-who! vector-set/copy
-  (lambda (v idx val)
-    (unless (vector? v)
-      ($oops who "~s is not a vector" v))
-    (unless (and (fixnum? idx) (fx<= 0 idx) (fx< idx (vector-length v)))
-      ($oops who "~s is not a valid index for ~s" idx v))
-    (#3%vector-set/copy v idx val)))
+       (append-vectors who vs)]))
+
+  (set-who! immutable-vector-append
+    (case-lambda
+      [(v)
+       (unless (vector? v) (not-a-vector who v))
+       (immutable-vector-copy v)]
+      [(v1 v2)
+       (unless (vector? v1) (not-a-vector who v1))
+       (unless (vector? v2) (not-a-vector who v2))
+       (#3%immutable-vector-append v1 v2)]
+      [(v1 v2 v3)
+       (unless (vector? v1) (not-a-vector who v1))
+       (unless (vector? v2) (not-a-vector who v2))
+       (unless (vector? v3) (not-a-vector who v3))
+       (#3%immutable-vector-append v1 v2 v3)]
+      [vs
+       (let ([v (append-vectors who vs)])
+         (cond
+           [(eq? v '#())
+            (immutable-vector)]
+           [else
+            ($vector-set-immutable! v)
+            v]))]))
+
+  (set-who! vector-set/copy
+    (lambda (v idx val)
+      (unless (vector? v) (not-a-vector who v))
+      (unless (and (fixnum? idx) (fx<= 0 idx) (fx< idx (vector-length v)))
+        ($oops who "~s is not a valid index for ~s" idx v))
+      (#3%vector-set/copy v idx val)))
+
+  (set-who! immutable-vector-set/copy
+    (lambda (v idx val)
+      (unless (vector? v) (not-a-vector who v))
+      (unless (and (fixnum? idx) (fx<= 0 idx) (fx< idx (vector-length v)))
+        ($oops who "~s is not a valid index for ~s" idx v))
+      (#3%immutable-vector-set/copy v idx val))))
 
 (set! vector->list
   (lambda (v)
@@ -116,14 +160,8 @@
 
 (set-who! vector->immutable-vector
   (lambda (v)
-    (cond
-      [(immutable-vector? v) v]
-      [(eqv? v '#()) (vector->immutable-vector '#())]
-      [else
-       (unless (vector? v) ($oops who "~s is not a vector" v))
-       (let ([v2 (vector-copy v)])
-         ($vector-set-immutable! v2)
-         v2)])))
+    (unless (vector? v) ($oops who "~s is not a vector" v))
+    (#3%vector->immutable-vector v)))
 
 (set-who! vector-fill!
   (lambda (v obj)
diff --git a/s/base-lang.ss b/s/base-lang.ss
index 7b4c053b1..b3066ac3f 100644
--- a/s/base-lang.ss
+++ b/s/base-lang.ss
@@ -217,7 +217,7 @@
 
   ; source language used by the passes leading up to the compiler or interpreter
   (define-language Lsrc
-    (nongenerative-id #{Lsrc e9hk42fhc9m126ci6byqksp4h-0})
+    (nongenerative-id #{Lsrc e9hk42fhc9m126ci6byqksp4h-5})
     (terminals
       (preinfo (preinfo))
       ($prelex (x))
@@ -251,6 +251,7 @@
       (record-type rtd e)
       (record-cd rcd rtd-expr e)
       (immutable-list (e* ...) e)
+      (immutable-vector (e* ...) e)
       (record rtd rtd-expr e* ...)
       (record-ref rtd type index e)
       (record-set! rtd type index e1 e2)
diff --git a/s/cmacros.ss b/s/cmacros.ss
index ae5272659..efa63484e 100644
--- a/s/cmacros.ss
+++ b/s/cmacros.ss
@@ -357,7 +357,7 @@
 ;; ---------------------------------------------------------------------
 ;; Version and machine types:
 
-(define-constant scheme-version #x09090917)
+(define-constant scheme-version #x09090918)
 
 (define-syntax define-machine-types
   (lambda (x)
diff --git a/s/cp0.ss b/s/cp0.ss
index 2cd06d408..a27908c67 100644
--- a/s/cp0.ss
+++ b/s/cp0.ss
@@ -1078,6 +1078,8 @@
                            `(record ,rtd ,rtd-expr ,e* ...)]
                           [(immutable-list (,[e*] ...) ,[e])
                            `(immutable-list (,e* ...) ,e)]
+                          [(immutable-vector (,[e*] ...) ,[e])
+                           `(immutable-vector (,e* ...) ,e)]
                           [(pariah) e]
                           [(profile ,src) e]
                           [else (exit #f)]))))
@@ -1180,6 +1182,7 @@
               [(foreign (,conv* ...) ,name ,e (,arg-type* ...) ,result-type) (memoize (pure? e))]
               [(letrec* ([,x* ,e*] ...) ,body) (memoize (and (andmap pure1? e*) (pure? body)))]
               [(immutable-list (,e* ...) ,e) (memoize (and (andmap pure1? e*) (pure? e)))]
+              [(immutable-vector (,e* ...) ,e) (memoize (and (andmap pure1? e*) (pure? e)))]
               [(profile ,src) #t]
               [(cte-optimization-loc ,box ,e ,exts) (memoize (pure? e))]
               [(moi) #t]
@@ -1244,6 +1247,7 @@
               [(foreign (,conv* ...) ,name ,e (,arg-type* ...) ,result-type) (memoize (ivory1? e))]
               [(letrec* ([,x* ,e*] ...) ,body) (memoize (and (andmap ivory1? e*) (ivory? body)))]
               [(immutable-list (,e* ...) ,e) (memoize (and (andmap ivory1? e*) (ivory? e)))]
+              [(immutable-vector (,e* ...) ,e) (memoize (and (andmap ivory1? e*) (ivory? e)))]
               [(profile ,src) #t]
               [(cte-optimization-loc ,box ,e ,exts) (memoize (ivory? e))]
               [(moi) #t]
@@ -1284,6 +1288,7 @@
               [(seq ,e1 ,e2) (memoize (and (simple? e1) (simple? e2)))]
               [(set! ,maybe-src ,x ,e) #f]
               [(immutable-list (,e* ...) ,e) (memoize (and (andmap simple1? e*) (simple? e)))]
+              [(immutable-vector (,e* ...) ,e) (memoize (and (andmap simple1? e*) (simple? e)))]
               [(letrec ([,x* ,e*] ...) ,body) (memoize (and (andmap simple1? e*) (simple? body)))]
               [(letrec* ([,x* ,e*] ...) ,body) (memoize (and (andmap simple1? e*) (simple? body)))]
               [,pr #t]
@@ -1335,6 +1340,7 @@
               [(seq ,e1 ,e2) (memoize (and (simple/profile? e1) (simple/profile? e2)))]
               [(set! ,maybe-src ,x ,e) #f]
               [(immutable-list (,e* ...) ,e) (memoize (and (andmap simple/profile1? e*) (simple/profile? e)))]
+              [(immutable-vector (,e* ...) ,e) (memoize (and (andmap simple/profile1? e*) (simple/profile? e)))]
               [(letrec ([,x* ,e*] ...) ,body) (memoize (and (andmap simple/profile1? e*) (simple/profile? body)))]
               [(letrec* ([,x* ,e*] ...) ,body) (memoize (and (andmap simple/profile1? e*) (simple/profile? body)))]
               [,pr #t]
@@ -1418,6 +1424,7 @@
               [(record-set! ,rtd ,type ,index ,e1 ,e2) #f]
               [(record ,rtd ,rtd-expr ,e* ...) #f]
               [(immutable-list (,e* ...) ,e) #f]
+              [(immutable-vector (,e* ...) ,e) #f]
               [(cte-optimization-loc ,box ,e ,exts) (memoize (boolean-valued? e))]
               [(profile ,src) #f]
               [(set! ,maybe-src ,x ,e) #f]
@@ -1508,6 +1515,7 @@
               [(seq ,e1 ,e2) (memoize (single-valued e2))]
               [(set! ,maybe-src ,x ,e) #t]
               [(immutable-list (,e* ...) ,e) #t]
+              [(immutable-vector (,e* ...) ,e) #t]
               [(letrec ([,x* ,e*] ...) ,body) (memoize (single-valued body))]
               [(letrec* ([,x* ,e*] ...) ,body) (memoize (single-valued body))]
               [,pr #t]
@@ -1697,6 +1705,14 @@
                     ; (let ((x e)) x) => e
                     ; x is clearly not assigned, even if flags are polluted and say it is
                     (make-nontail (app-ctxt ctxt) (car rhs*))]
+                   [(and (= (length id*) 1)
+                         (= (length rhs*) 1)
+                         (nanopass-case (Lsrc Expr) (car rhs*)
+                           [(seq ,e1 ,e2)
+                            ; (let ((x (begin e1 e2))) e3) => (begin e1 (let ((x e2)) e3))
+                            ; this can expose (immutable-vector ...) in e2 to optimization
+                            `(seq ,e1 ,(build-let lambda-preinfo id* (list e2) body))]
+                           [else #f]))]
                    ; we drop the RHS of a let binding into the let body when the body expression is a call 
                    ; and we can do so without violating evaluation order of bindings wrt the let body:
                    ;  * for pure, singly referenced bindings, we drop them to the variable reference site
@@ -1961,6 +1977,19 @@
                       x]
                      [else id])
                    sc))]
+            [(immutable-vector (,e* ...) ,e)
+             `(immutable-vector (,e* ...)
+                ,(residualize-ref maybe-src
+                   (nanopass-case (Lsrc Expr) e
+                     [(ref ,maybe-src ,x)
+                      (guard (not (prelex-was-assigned x))
+                        ; protect against (letrec ([x x]) ---)
+                        (not (eq? x id)))
+                      (when (prelex-was-multiply-referenced id)
+                        (set-prelex-was-multiply-referenced! x #t))
+                      x]
+                     [else id])
+                   sc))]
             [(ref ,maybe-src1 ,x)
              (cond
                [(and (not (prelex-was-assigned x))
@@ -2634,6 +2663,42 @@
               empty-vector-rec)]
         [args #f])
 
+      (define-inline 2 immutable-vector
+        [() (begin
+              (residualize-seq '() '() ctxt)
+              `(quote ,(immutable-vector)))]
+        [opnd*
+         (or (let ([e* (objs-if-constant (value-visit-operands! opnd*))])
+               (and e*
+                    (begin
+                      (residualize-seq '() opnd* ctxt)
+                      `(quote ,(apply immutable-vector e*)))))
+             (begin
+               (residualize-seq opnd* '() ctxt)
+               (let loop ([e* (value-visit-operands! opnd*)]
+                          [lhs* '()]
+                          [rhs* '()]
+                          [re* '()])
+                 (if (null? e*)
+                     (let ([e* (reverse re*)])
+                       (let ([e `(immutable-vector (,e* ...)
+                                   ,(build-primcall 3 'immutable-vector e*))])
+                         (if (null? lhs*)
+                             e
+                             (build-let lhs* rhs* e))))
+                     (let ([e (car e*)] [e* (cdr e*)])
+                       (if (nanopass-case (Lsrc Expr) e
+                             [(quote ,d) #t]
+                             [(ref ,maybe-src ,x)
+                              (guard (not (prelex-was-assigned x)))
+                              (unless (prelex-multiply-referenced x)
+                                (set-prelex-multiply-referenced! x #t))
+                              #t]
+                             [else #f])
+                           (loop e* lhs* rhs* (cons e re*))
+                           (let ([t (cp0-make-temp #t)])
+                             (loop e* (cons t lhs*) (cons e rhs*) (cons (build-ref t) re*)))))))))])
+
       (define-inline 2 string
         [() (begin
               (residualize-seq '() '() ctxt)
@@ -2658,19 +2723,73 @@
               empty-flvector-rec)]
         [args #f])
 
-      (define-inline 2 vector->immutable-vector
-        [(e) (let ([e-val (value-visit-operand! e)])
-               (nanopass-case (Lsrc Expr) (result-exp e-val)
-                 [(quote ,d)
-                  (cond
-                    [(immutable-vector? d)
-                     (residualize-seq (list e) '() ctxt)
-                      e-val]
-                    [(eq? d '#())
-                     (residualize-seq '() (list e) ctxt)
-                     `(quote ,(vector->immutable-vector '#()))]
-                    [else #f])]
-                 [else #f]))])
+      (let ()
+        (define (build-immediate-immutable-vector e ctxt)
+          (let ([e-val (value-visit-operand! e)])
+            (nanopass-case (Lsrc Expr) (result-exp e-val)
+              [(quote ,d)
+               (cond
+                 [(immutable-vector? d)
+                  (residualize-seq (list e) '() ctxt)
+                  e-val]
+                 [(eq? d '#())
+                  (residualize-seq '() (list e) ctxt)
+                  `(quote ,(vector->immutable-vector '#()))]
+                 [else #f])]
+              [(immutable-vector (,e* ...) ,e2)
+               (residualize-seq (list e) '() ctxt)
+               e-val]
+              [(call ,preinfo ,pr ,e* ...)
+               (case (primref-name pr)
+                 [(vector->immutable-vector immutable-vector
+                                            immutable-vector-copy immutable-vector-set/copy immutable-vector-append)
+                  (residualize-seq (list e) '() ctxt)
+                  e-val]
+                 [(vector vector-copy vector-set/copy vector-append)
+                  (residualize-seq (list e) '() ctxt)
+                  (non-result-exp e-val
+                                  (build-primcall 3
+                                                  (case (primref-name pr)
+                                                    [(vector) 'immutable-vector]
+                                                    [(vector-copy) 'immutable-vector-copy]
+                                                    [(vector-set/copy) 'immutable-vector-set/copy]
+                                                    [(vector-append) 'immutable-vector-append]
+                                                    [else ($oops #f "missing conversion")])
+                                                  e*))]
+                 [else #f])]
+              [else #f])))
+        (define (build-append-immediate-vectors prim orig-vec-e* ctxt)
+          (let loop ([vec-e* orig-vec-e*] [accum '()])
+            (cond
+              [(null? vec-e*)
+               (residualize-seq orig-vec-e* '() ctxt)
+               (build-primcall 3 prim (reverse accum))]
+              [else
+               (let ([vec-e-val (value-visit-operand! (car vec-e*))])
+                 (nanopass-case (Lsrc Expr) vec-e-val
+                   [(quote ,d)
+                    (guard (vector? d))
+                    (loop (cdr vec-e*) (append (map (lambda (v) `(quote ,v))
+                                                    (reverse (vector->list d)))
+                                               accum))]
+                   [(immutable-vector (,e* ...) ,e)
+                    (loop (cdr vec-e*) (append (reverse e*) accum))]
+                   [(call ,preinfo ,pr ,e* ...)
+                    (guard (memq (primref-name pr) '(vector immutable-vector)))
+                    (loop (cdr vec-e*) (append (reverse e*) accum))]
+                   [else #f]))])))
+
+        (define-inline 2 vector->immutable-vector
+          [(e) (build-immediate-immutable-vector e ctxt)])
+        (define-inline 2 immutable-vector-copy
+          [(e) (build-immediate-immutable-vector e ctxt)])
+        (define-inline 2 vector-copy
+          [(e) (build-append-immediate-vectors 'vector (list e) ctxt)])
+        (define-inline 2 vector-append
+          [e* (build-append-immediate-vectors 'vector e* ctxt)])
+        (define-inline 2 immutable-vector-append
+          [(e) (build-immediate-immutable-vector e ctxt)]
+          [e* (build-append-immediate-vectors 'immutable-vector e* ctxt)]))
 
       (define-inline 2 string->immutable-string
         [(e) (let ([e-val (value-visit-operand! e)])
@@ -4046,6 +4165,7 @@
               [(fcallable (,conv* ...) ,e (,arg-type* ...) ,result-type) #t]
               [(record-set! ,rtd ,type ,index ,e1 ,e2) #t]
               [(immutable-list (,e* ...) ,e) #t]
+              [(immutable-vector (,e* ...) ,e) #t]
               [else #f])))
         (define one-arg-case
           (lambda (?x ctxt)
@@ -5044,7 +5164,25 @@
         (define true (lambda (x) #t))
 
         (define-inline 2 vector-ref
-          [(?x ?i) (tryref ctxt ?x ?i 'vector #f)])
+          [(?x ?i)
+           (or (nanopass-case (Lsrc Expr) (result-exp (value-visit-operand! ?x))
+                 [(immutable-vector (,e* ...) ,e)
+                  (nanopass-case (Lsrc Expr) (result-exp (value-visit-operand! ?i))
+                    [(quote ,d)
+                     (guard (fixnum? d) (#%$fxu< d (length e*)))
+                     (residualize-seq '() (app-opnds ctxt) ctxt)
+                     (list-ref e* d)]
+                    [else #f])]
+                 [else #f])
+               (tryref ctxt ?x ?i 'vector #f))])
+
+        (define-inline 2 vector-length
+          [(?x)
+           (nanopass-case (Lsrc Expr) (result-exp (value-visit-operand! ?x))
+             [(immutable-vector (,e* ...) ,e)
+              (residualize-seq '() (app-opnds ctxt) ctxt)
+              `(quote ,(length e*))]
+             [else #f])])
 
         (define-inline 2 string-ref
           [(?x ?i) (tryref ctxt ?x ?i 'string char?)])
@@ -5612,7 +5750,15 @@
       [(record-type ,rtd ,e) (cp0 e ctxt env sc wd name moi)]
       [(record-cd ,rcd ,rtd-expr ,e) (cp0 e ctxt env sc wd name moi)]
       [(immutable-list (,[cp0 : e* 'value env sc wd #f moi -> e*] ...) ,[cp0 : e ctxt env sc wd name moi -> e])
-       `(immutable-list (,e*  ...) ,e)]
+       (context-case ctxt
+         [(effect) (make-seq ctxt e void-rec)]
+         [(test) (make-seq ctxt e true-rec)]
+         [else `(immutable-list (,e*  ...) ,e)])]
+      [(immutable-vector (,[cp0 : e* 'value env sc wd #f moi -> e*] ...) ,[cp0 : e ctxt env sc wd name moi -> e])
+       (context-case ctxt
+         [(effect) (make-seq ctxt e void-rec)]
+         [(test) (make-seq ctxt e true-rec)]
+         [else `(immutable-vector (,e*  ...) ,e)])]
       [(moi) (if moi `(quote ,moi) ir)]
       [(pariah) ir]
       [(cte-optimization-loc ,box ,[cp0 : e ctxt env sc wd name moi -> e] ,exts)
diff --git a/s/cpcheck.ss b/s/cpcheck.ss
index 91d88598b..67290d5ba 100644
--- a/s/cpcheck.ss
+++ b/s/cpcheck.ss
@@ -215,6 +215,7 @@
                         ...)))))))]
       [(cte-optimization-loc ,box ,[e #f -> e] ,exts) e]
       [(immutable-list (,e* ...) ,[e]) e]
+      [(immutable-vector (,e* ...) ,[e]) e]
       [(moi) ir]
       [(pariah) ir]
       [(profile ,src) ir]
diff --git a/s/cpcommonize.ss b/s/cpcommonize.ss
index 18ef45661..9cf63bed2 100644
--- a/s/cpcommonize.ss
+++ b/s/cpcommonize.ss
@@ -117,6 +117,8 @@
          (values `(cte-optimization-loc ,box ,e ,exts) size)]
         [(immutable-list (,[e* size*] ...) ,[e size])
          (values `(immutable-list (,e* ...) ,e) (apply fx+ size size*))]
+        [(immutable-vector (,[e* size*] ...) ,[e size])
+         (values `(immutable-vector (,e* ...) ,e) (apply fx+ size size*))]
         [(quote ,d) (values `(quote ,d) 1)]
         [(ref ,maybe-src ,x) (values `(ref ,maybe-src ,x) 1)]
         [,pr (values pr 1)]
diff --git a/s/cpletrec.ss b/s/cpletrec.ss
index 070d052e1..d2aad9cdc 100644
--- a/s/cpletrec.ss
+++ b/s/cpletrec.ss
@@ -387,6 +387,8 @@ Handling letrec and letrec*
       [(record-cd ,rcd ,rtd-expr ,e) (Expr e)]
       [(immutable-list (,[e* pure?*] ...) ,[e pure?])
        (values `(immutable-list (,e* ...) ,e) pure?)]
+      [(immutable-vector (,[e* pure?*] ...) ,[e pure?])
+       (values `(immutable-vector (,e* ...) ,e) pure?)]
       [,pr (values pr #t)]
       [(moi) (values ir #t)]
       [(pariah) (values ir #t)]
diff --git a/s/cpnanopass.ss b/s/cpnanopass.ss
index fa8bf1cfa..45bc380bc 100644
--- a/s/cpnanopass.ss
+++ b/s/cpnanopass.ss
@@ -6250,12 +6250,16 @@
                                         (set! ,%ac0 ,%xp)
                                         (jump ,%ref-ret (,%ac0)))
                                      ,(f (cdr reg*) (fx+ i 1))))))))))]
-           [(vector-procedure)
-            (let ([Ltop (make-local-label 'ltop)])
-              `(lambda ,(make-info "vector" '(-1) #t) 0 ()
+           [(vector-procedure immutable-vector-procedure)
+            (let* ([Ltop (make-local-label 'ltop)]
+                   [mut? (eq? sym 'vector-procedure)]
+                   [constant-type-*vector (if mut?
+                                              (constant type-vector)
+                                              (constant type-immutable-vector))])
+              `(lambda ,(make-info (if mut? "vector" "immutable-vector") '(-1) #t) 0 ()
                  (if ,(%inline eq? ,%ac0 (immediate 0))
                      ,(%seq
-                        (set! ,%ac0 (literal ,(make-info-literal #f 'object '#() 0)))
+                        (set! ,%ac0 (literal ,(make-info-literal #f 'object (if mut? '#() (vector->immutable-vector '#())) 0)))
                         (jump ,%ref-ret (,%ac0)))
                      ,(%seq
                         (set! ,%ac0 ,(%inline sll ,%ac0 ,(%constant log2-ptr-bytes)))
@@ -6265,17 +6269,17 @@
                         ,(let ([delta (fx- (constant vector-length-offset) (constant log2-ptr-bytes))])
                            (safe-assert (fx>= delta 0))
                            (if (fx= delta 0)
-                               (if (fx= (constant type-vector) 0)
+                               (if (fx= constant-type-*vector 0)
                                    `(set! ,(%mref ,%xp ,(constant vector-type-disp)) ,%ac0)
                                    (%seq
-                                     (set! ,%td ,(%inline logor ,%ac0 (immediate ,(constant type-vector))))
+                                     (set! ,%td ,(%inline logor ,%ac0 (immediate ,constant-type-*vector)))
                                      (set! ,(%mref ,%xp ,(constant vector-type-disp)) ,%td)))
                                (%seq
                                  (set! ,%td ,(%inline sll ,%ac0 (immediate ,delta)))
-                                 ,(if (fx= (constant type-vector) 0)
+                                 ,(if (fx= constant-type-*vector 0)
                                       `(set! ,(%mref ,%xp ,(constant vector-type-disp)) ,%td)
                                       (%seq
-                                        (set! ,%td ,(%inline logor ,%td (immediate ,(constant type-vector))))
+                                        (set! ,%td ,(%inline logor ,%td (immediate ,constant-type-*vector)))
                                         (set! ,(%mref ,%xp ,(constant vector-type-disp)) ,%td))))))
                         ,(let f ([reg* arg-registers] [i 0])
                            (if (null? reg*)
diff --git a/s/cpprim.ss b/s/cpprim.ss
index a9bb94525..b1b92ae27 100644
--- a/s/cpprim.ss
+++ b/s/cpprim.ss
@@ -7351,27 +7351,27 @@
       (meta-assert (= (constant log2-ptr-bytes) (constant fixnum-offset)))
       (let ()
         (define do-make-vector
-          (lambda (e-length e-fill)
+          (lambda (type e-length e-fill)
             ; NB: caller must bind e-fill, if not #f
             (safe-assert (or (not e-fill) (no-need-to-bind? #f e-fill)))
             (if (constant? (lambda (x) (and (fixnum? x) (fx<= 0 x 10000))) e-length)
                 (let ([n (constant-value e-length)])
                   (if (fx= n 0)
-                      `(quote ,(vector))
+                      `(quote ,(if (fx= type (constant type-vector)) (vector) (immutable-vector)))
                       (let ([bytes (fx* n (constant ptr-bytes))])
                         (bind #t ([t (%constant-alloc type-typed-object
                                        (fx+ (constant header-size-vector) bytes))])
                           `(seq
                              (set! ,(%mref ,t ,(constant vector-type-disp))
                                (immediate ,(+ (fx* n (constant vector-length-factor))
-                                              (constant type-vector))))
+                                              type)))
                              ,(if e-fill
                                   (build-vector-fill t `(immediate ,bytes) e-fill)
                                   t))))))
                 (bind #t (e-length) ; fixnum length doubles as byte count
                   (let ([t-vec (make-tmp 'tvec)])
                     `(if ,(%inline eq? ,e-length (immediate 0))
-                         (quote ,(vector))
+                         (quote ,(if (fx= type (constant type-vector)) (vector) (immutable-vector)))
                          (let ([,t-vec (alloc ,(make-info-alloc (constant type-typed-object) #f #f)
                                          ,(%inline logand
                                             ,(%inline + ,e-length
@@ -7381,7 +7381,7 @@
                            (seq
                              (set! ,(%mref ,t-vec ,(constant vector-type-disp))
                                ,(build-type/length e-length
-                                  (constant type-vector)
+                                  type
                                   (constant fixnum-offset)
                                   (constant vector-length-offset)))
                              ,(if e-fill
@@ -7389,50 +7389,75 @@
                                   t-vec)))))))))
         (define default-fill `(immediate ,(fix 0)))
         (define-inline 3 make-vector
-          [(e-length) (do-make-vector e-length default-fill)]
-          [(e-length e-fill) (bind #t (e-fill) (do-make-vector e-length e-fill))])
+          [(e-length) (do-make-vector (constant type-vector) e-length default-fill)]
+          [(e-length e-fill) (bind #t (e-fill) (do-make-vector (constant type-vector) e-length e-fill))])
         (let ()
           (define (extract-vector-length vec)
             (extract-length (%mref ,vec ,(constant vector-type-disp)) (constant vector-length-offset)))
           (define build-vector-copy
-            (lambda (e-vec e-start e-len e-elem prefix-elem?)
+            (lambda (type e-vec e-start e-len e-elem prefix-elem? n-elem)
               (let ([Ltop (make-local-label 'Ltop)]
                     [vec (make-tmp 'vec 'ptr)]
                     [t (make-assigned-tmp 't 'uptr)])
                 (bind #t (e-vec e-start e-len)
                   `(let ([,t (immediate 0)]
                          [,vec ,(if (not e-elem)
-                                    (do-make-vector e-len #f)
+                                    (do-make-vector type e-len #f)
                                     (let ([total-len (make-tmp 'total-len 'uptr)])
-                                      `(let ([,total-len ,(%inline + ,e-len (immediate ,(fix 1)))])
-                                         ,(do-make-vector total-len #f))))])
+                                      `(let ([,total-len ,(%inline + ,e-len ,n-elem)])
+                                         ,(do-make-vector type total-len #f))))])
                      (label ,Ltop
                        (if ,(%inline eq? ,t ,e-len)
                            ,(cond
-                              [(not e-elem) vec]
-                              [else
-                               (let ([idx (if prefix-elem? `(immediate 0) e-len)])
-                                 (%seq
-                                  (set! ,(%mref ,vec ,idx ,(constant vector-data-disp)) ,e-elem)
-                                  ,vec))])
+                             [(not e-elem) vec]
+                             [(nanopass-case (L7 Expr) n-elem
+                                [(immediate ,imm) (guard (eqv? imm (fix 1))) #t]
+                                [(quote ,d) (guard (eqv? d 1)) #t]
+                                [else #f])
+                              (let ([idx (if prefix-elem? `(immediate 0) e-len)])
+                                (%seq
+                                 (set! ,(%mref ,vec ,idx ,(constant vector-data-disp)) ,e-elem)
+                                 ,vec))]
+                             [else
+                              (let ([Lfill (make-local-label 'Lfill)]
+                                    [idx (if prefix-elem?
+                                             t
+                                             (with-output-language (L7 Expr)
+                                               (%inline + ,t ,e-len)))])
+                                (%seq
+                                 (set! ,t (immediate 0))
+                                 (label ,Lfill
+                                   (if ,(%inline eq? ,t ,n-elem)
+                                       ,vec
+                                       ,(%seq
+                                         (set! ,(%mref ,vec ,idx ,(constant vector-data-disp)) ,e-elem)
+                                         (set! ,t ,(%inline + ,t (immediate ,(constant ptr-bytes))))
+                                         (goto ,Lfill))))))])
                            ,(%seq
                              (set! ,(let ([idx (if prefix-elem?
                                                    (with-output-language (L7 Expr)
-                                                     (%inline + ,t (immediate ,(fix 1))))
+                                                     (%inline + ,t ,n-elem))
                                                    t)])
                                       (%mref ,vec ,idx ,(constant vector-data-disp)))
                                    ,(%mref ,e-vec ,(%inline + ,t ,e-start) ,(constant vector-data-disp)))
                              (set! ,t ,(%inline + ,t (immediate ,(constant ptr-bytes))))
                              (goto ,Ltop)))))))))
+          (define build-immutable-vector-copy
+            (lambda (vec)
+              (bind #t (vec)
+                `(if ,(%typed-object-check mask-mutable-vector type-immutable-vector ,vec)
+                     ,vec
+                     ,(build-vector-copy (constant type-immutable-vector) vec
+                                         `(immediate ,(fix 0)) (extract-vector-length vec) #f #f #f)))))
           (define build-vector-set/copy
-            (lambda (e-vec e-idx e-val)
+            (lambda (type e-vec e-idx e-val)
               (let ([Ltop (make-local-label 'Ltop)]
                     [vec (make-tmp 'vec 'ptr)]
                     [t (make-assigned-tmp 't 'uptr)])
                 (bind #t (e-vec e-idx)
                   (bind #f (e-val)
                     `(let ([,t ,(extract-vector-length e-vec)])
-                       (let ([,vec ,(do-make-vector t #f)])
+                       (let ([,vec ,(do-make-vector type t #f)])
                          (label ,Ltop
                            (if ,(%inline eq? ,t (immediate 0))
                                ,(%seq
@@ -7444,11 +7469,11 @@
                                        ,(%mref ,e-vec ,t ,(constant vector-data-disp)))
                                  (goto ,Ltop)))))))))))
           (define build-vector-append
-            (lambda (e-vecs)
+            (lambda (type e-vecs)
               (let loop ([e-vecs e-vecs] [len `(immediate 0)])
                 (cond
                   [(null? e-vecs)
-                   (do-make-vector len #f)]
+                   (do-make-vector type len #f)]
                   [else
                    (let ([Ltop (make-local-label 'Ltop)]
                          [d-vec (make-tmp 'd-vec 'ptr)]
@@ -7467,29 +7492,56 @@
                                          (set! ,(%mref ,d-vec ,(%inline + ,t ,e-len) ,(constant vector-data-disp))
                                                ,(%mref ,e-vec ,e-len ,(constant vector-data-disp)))
                                          (goto ,Ltop))))))))]))))
+          (define (okay-make-vector? pr e1)
+            (and (eq? (primref-name pr) 'make-vector)
+                 (or (>= (primref-level pr) 3)
+                     (constant? (lambda (x) (and (target-fixnum? x) (>= x 0))) e1))))
+          (define build-vector-append-two
+            (lambda (type vec1 vec2)
+              (nanopass-case (L7 Expr) vec1
+                [(call ,info1 ,mdcl1 ,pr ,e1)
+                 (guard (memq (primref-name pr) '(vector immutable-vector)))
+                 (bind #f (e1)
+                   (bind #t (vec2)
+                     (build-vector-copy type vec2 `(immediate ,(fix 0)) (extract-vector-length vec2) e1 #t `(immediate ,(fix 1)))))]
+                [(call ,info1 ,mdcl1 ,pr ,e1 ,e2)
+                 (guard (okay-make-vector? pr e1))
+                 (bind #t (e1 e2 vec2)
+                   (build-vector-copy type vec2 `(immediate ,(fix 0)) (extract-vector-length vec2) e2 #t e1))]
+                [else
+                 (nanopass-case (L7 Expr) vec2
+                   [(call ,info2 ,mdcl2 ,pr ,e2)
+                    (guard (memq (primref-name pr) '(vector immutable-vector)))
+                    (bind #t (vec1)
+                      (bind #f (e2)
+                        (build-vector-copy type vec1 `(immediate ,(fix 0)) (extract-vector-length vec1) e2 #f `(immediate ,(fix 1)))))]
+                   [(call ,info2 ,mdcl2 ,pr ,e1 ,e2)
+                    (guard (okay-make-vector? pr e1))
+                    (bind #t (e1 e2 vec1)
+                      (build-vector-copy type vec1 `(immediate ,(fix 0)) (extract-vector-length vec1) e2 #f e1))]
+                   [else (build-vector-append type (list vec1 vec2))])])))
           (define-inline 3 vector-copy
             [(vec) (bind #t (vec)
-                     (build-vector-copy vec `(immediate ,(fix 0)) (extract-vector-length vec) #f #f))]
-            [(vec start len) (build-vector-copy vec start len #f #f)])
+                     (build-vector-copy (constant type-vector) vec `(immediate ,(fix 0)) (extract-vector-length vec) #f #f #f))]
+            [(vec start len) (build-vector-copy (constant type-vector) vec start len #f #f #f)])
+          (define-inline 3 immutable-vector-copy
+            [(vec) (build-immutable-vector-copy vec)]
+            [(vec start len) (build-vector-copy (constant type-immutable-vector) vec start len #f #f #f)])
+          (define-inline 3 vector->immutable-vector
+            [(vec) (build-immutable-vector-copy vec)])
           (define-inline 3 vector-set/copy
-            [(vec idx val) (build-vector-set/copy vec idx val)])
+            [(vec idx val) (build-vector-set/copy (constant type-vector) vec idx val)])
+          (define-inline 3 immutable-vector-set/copy
+            [(vec idx val) (build-vector-set/copy (constant type-immutable-vector) vec idx val)])
           (define-inline 3 vector-append
             [() `(quote ,(vector))]
-            [(vec1 vec2) (nanopass-case (L7 Expr) vec1
-                           [(call ,info1 ,mdcl1 ,pr ,e1)
-                            (guard (eq? (primref-name pr) 'vector))
-                            (bind #f (e1)
-                              (bind #t (vec2)
-                                (build-vector-copy vec2 `(immediate ,(fix 0)) (extract-vector-length vec2) e1 #t)))]
-                           [else
-                            (nanopass-case (L7 Expr) vec2
-                              [(call ,info2 ,mdcl2 ,pr ,e2)
-                               (guard (eq? (primref-name pr) 'vector))
-                               (bind #t (vec1)
-                                 (bind #f (e2)
-                                   (build-vector-copy vec1 `(immediate ,(fix 0)) (extract-vector-length vec1) e2 #f)))]
-                              [else (build-vector-append (list vec1 vec2))])])]
-            [(vec . vecs) (build-vector-append (cons vec vecs))]))
+            [(vec1 vec2) (build-vector-append-two (constant type-vector) vec1 vec2)]
+            [(vec . vecs) (build-vector-append (constant type-vector) (cons vec vecs))])
+          (define-inline 3 immutable-vector-append
+            [() `(quote ,(immutable-vector))]
+            [(vec) (build-immutable-vector-copy vec)]
+            [(vec1 vec2) (build-vector-append-two (constant type-immutable-vector) vec1 vec2)]
+            [(vec . vecs) (build-vector-append (constant type-immutable-vector) (cons vec vecs))]))
         (let ()
           (define (valid-length? e-length)
             (constant?
@@ -7498,11 +7550,11 @@
           (define-inline 2 make-vector
             [(e-length)
              (and (valid-length? e-length)
-                  (do-make-vector e-length default-fill))]
+                  (do-make-vector (constant type-vector) e-length default-fill))]
             [(e-length e-fill)
              (and (valid-length? e-length)
                   (constant? fixnum? e-fill)
-                  (do-make-vector e-length e-fill))]))
+                  (do-make-vector (constant type-vector) e-length e-fill))]))
         (define-inline 2 vector->immutable-vector
           [(e-vec)
            (nanopass-case (L7 Expr) e-vec
diff --git a/s/cprep.ss b/s/cprep.ss
index df2896a5e..1917a20d2 100644
--- a/s/cprep.ss
+++ b/s/cprep.ss
@@ -226,6 +226,7 @@
                [(record-type ,rtd ,[e]) `(record-type ,rtd ,e)]
                [(record-cd ,rcd ,rtd-expr ,[e]) `(record-cd ,rcd ,e)]
                [(immutable-list (,e* ...) ,[e]) e]
+               [(immutable-vector (,e* ...) ,[e]) e]
                [(moi) ''moi]
                [(pariah) `(pariah (void))]
                [(profile ,src) `(void)]
diff --git a/s/cptypes.ss b/s/cptypes.ss
index d32766b6a..dd681c068 100644
--- a/s/cptypes.ss
+++ b/s/cptypes.ss
@@ -125,6 +125,7 @@ Notes:
                  [(case-lambda ,preinfo ,cl* ...) #t]
                  [(set! ,maybe-src ,x ,e) #t]
                  [(immutable-list (,e* ...) ,e) #t]
+                 [(immutable-vector (,e* ...) ,e) #t]
                  [,pr #t]
                  [(record-cd ,rcd ,rtd-expr ,e) #t]
                  [(record-ref ,rtd ,type ,index ,e) #t]
@@ -204,6 +205,8 @@ Notes:
            (make-1seq 'effect rtd-expr e void-rec)]
           [(immutable-list (,e* ...) ,e)
            (make-1seq 'effect (make-1seq* 'effect e*) e void-rec)]
+          [(immutable-vector (,e* ...) ,e)
+           (make-1seq 'effect (make-1seq* 'effect e*) e void-rec)]
           [(moi) void-rec]
           [else ir]
           #;[else ($oops who "unrecognized record ~s" ir)])
@@ -1888,6 +1891,10 @@ Notes:
                        ,[e 'value types plxc -> e ret types t-types f-types])
        (values `(immutable-list (,e*  ...) ,e)
                (if (null? e*) null-rec '$list-pair) types #f #f)]
+      [(immutable-vector (,[e* 'value types plxc -> e* r* t* t-t* f-t*] ...)
+                         ,[e 'value types plxc -> e ret types t-types f-types])
+       (values `(immutable-vector (,e*  ...) ,e)
+               ret types t-types f-types)]
       [(moi) (values ir #f types #f #f)]
       [(pariah) (values ir void-rec types #f #f)]
       [(cte-optimization-loc ,box ,[e 'value types plxc -> e ret types t-types f-types] ,exts)
diff --git a/s/primdata.ss b/s/primdata.ss
index 95bcaf9a7..ca44522a6 100644
--- a/s/primdata.ss
+++ b/s/primdata.ss
@@ -327,7 +327,7 @@
   (vector? [sig [(ptr) -> (boolean)]] [pred vector] [flags pure unrestricted mifoldable discard ieee r5rs])
   (make-vector [sig [(length) (length ptr) -> (vector)]] [flags alloc ieee r5rs])
   (vector [sig [(ptr ...) -> (vector)]] [flags unrestricted alloc ieee r5rs cp02])
-  (vector-length [sig [(vector) -> (length)]] [flags pure true ieee r5rs mifoldable discard safeongoodargs])
+  (vector-length [sig [(vector) -> (length)]] [flags pure true ieee r5rs mifoldable discard safeongoodargs cp02])
   (vector-ref [sig [(nonempty-vector sub-index) -> (ptr)]] [flags ieee r5rs mifoldable discard cp02])
   (vector-set! [sig [(nonempty-vector sub-index ptr) -> (void)]] [flags true ieee r5rs cptypes2])
   (vector->list [sig [(vector) -> (list)]] [flags alloc safeongoodargs ieee r5rs])
@@ -1457,6 +1457,10 @@
   (ieee-environment [sig [() -> (environment)]] [flags unrestricted alloc])
   (immutable-string? [sig [(ptr) -> (boolean)]] [pred immutable-string] [flags pure unrestricted mifoldable discard])
   (immutable-box? [sig [(ptr) -> (boolean)]] [pred immutable-box] [flags pure unrestricted mifoldable discard])
+  (immutable-vector [sig [(ptr ...) -> (immutable-vector)]] [flags unrestricted pure mifoldable alloc cp02])
+  (immutable-vector-append [sig [(vector ...) -> (immutable-vector)]] [flags alloc safeongoodargs cp02])
+  (immutable-vector-copy [sig [(vector) -> (immutable-vector)] [(vector sub-length sub-length) -> (immutable-vector)]] [flags alloc cp02])
+  (immutable-vector-set/copy [sig [(nonempty-vector sub-index ptr) -> (immutable-vector)]] [flags alloc])
   (immutable-vector? [sig [(ptr) -> (boolean)]] [pred immutable-vector] [flags pure unrestricted mifoldable discard])
   (immutable-bytevector? [sig [(ptr) -> (boolean)]] [pred immutable-bytevector] [flags pure unrestricted mifoldable discard])
   (initial-bytes-allocated [sig [() -> (uint)]] [flags unrestricted alloc])
@@ -1831,9 +1835,9 @@
   (utf-16-codec [sig [() -> (codec)] [(sub-symbol) -> (codec)]] [flags pure true]) ; has optional eness argument
   (utf-16le-codec [sig [() -> (codec)]] [flags pure unrestricted true])
   (utf-16be-codec [sig [() -> (codec)]] [flags pure unrestricted true])
-  (vector-append [sig [(vector ...) -> (vector)]] [flags alloc safeongoodargs])
+  (vector-append [sig [(vector ...) -> (vector)]] [flags alloc safeongoodargs cp02])
   (vector-cas! [sig [(nonempty-vector sub-index ptr ptr) -> (boolean)]] [flags cptypes2])
-  (vector-copy [sig [(vector) -> (vector)] [(vector sub-length sub-length) -> (vector)]] [flags alloc])
+  (vector-copy [sig [(vector) -> (vector)] [(vector sub-length sub-length) -> (vector)]] [flags alloc cp02])
   (vector->immutable-vector [sig [(vector) -> (immutable-vector)]] [flags alloc cp02 safeongoodargs])
   (vector->pseudo-random-generator [sig [(nonempty-vector) -> (pseudo-random-generator)]] [flags])
   (vector->pseudo-random-generator! [sig [(pseudo-random-generator nonempty-vector) -> (void)]] [flags])
diff --git a/s/prims.ss b/s/prims.ss
index d0452deb9..fb925609d 100644
--- a/s/prims.ss
+++ b/s/prims.ss
@@ -29,6 +29,7 @@
 (define list ($hand-coded 'list-procedure))
 (define $record ($hand-coded '$record-procedure))
 (define vector ($hand-coded 'vector-procedure))
+(define immutable-vector ($hand-coded 'immutable-vector-procedure))
 (define cons* ($hand-coded 'cons*-procedure))
 (define list* ($hand-coded 'list*-procedure))
 (define $apply ($hand-coded '$apply-procedure))
diff --git a/s/reboot.ss b/s/reboot.ss
index 8a8d76501..8dbe02a80 100644
--- a/s/reboot.ss
+++ b/s/reboot.ss
@@ -311,6 +311,7 @@
 (define-primitive $stencil-vector? (lambda (v) #f))
 (define-primitive $system-stencil-vector? (lambda (v) #f))
 (define-primitive $symbol-name #%$symbol-name)
+(define-primitive immutable-vector (lambda args (vector->immutable-vector (apply vector args))))
 
 (define-primitive ($char-grapheme-other-state) 1) ; probably correct, shouldn't matter for compiler
 
diff --git a/s/syntax.ss b/s/syntax.ss
index e8b1a4801..197d1b10c 100644
--- a/s/syntax.ss
+++ b/s/syntax.ss
@@ -8323,9 +8323,9 @@
                    (lambda () expr)
                    (rec define-values-consumer
                      #,(if (or (= (optimize-level) 3) (identifier? #'formals))
-                           #'(lambda formals (vector ffml ...))
+                           #'(lambda formals (immutable-vector ffml ...))
                            #`(case-lambda
-                               [formals (vector ffml ...)]
+                               [formals (immutable-vector ffml ...)]
                                [args #,($make-source-oops #'define-values
                                          "incorrect number of values from rhs"
                                          #'expr)])))))