LieTypes ring check

Macaulay2 · Sep 16, 2023 · fd56f9c · fd56f9c
1 parent ef5b185
commit fd56f9c
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/M2/Macaulay2/packages/LieTypes.m2 b/M2/Macaulay2/packages/LieTypes.m2
@@ -1361,6 +1361,7 @@ subLieAlgebra (LieAlgebra, List) := (g,S) -> subLieAlgebra(g,if #S==0 then map(Z
 *-
 
 subLieAlgebra (LieAlgebra,Matrix) := (g,M) -> ( -- matrix of coroots
+    if ring M =!= ZZ then try M=lift(M,ZZ) else error "matrix must be integer";
     -- in the simply laced case it'd be simply transpose M * cartanMatrix g * M. in general have to work harder
     if numRows M != rank g then error "wrong size of coroots";
     G := transpose M * inverse quadraticFormMatrix g * M; -- new inverse quadratic form <coroot_i|coroot_j>