diff --git a/TODO.md b/TODO.md
index 58b23257..1e7057aa 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,3 +1,5 @@
+[mod] extract `modBuildNet`
+
 `NodeDefinition` should not have `rules` -- use `RuleDefinition`
 
 `Node` should not have `definition` -- which is used to `getRule`
diff --git a/src/lang/definitions/NodeDefinition.ts b/src/lang/definitions/NodeDefinition.ts
index c8688fdc..217ae2e0 100644
--- a/src/lang/definitions/NodeDefinition.ts
+++ b/src/lang/definitions/NodeDefinition.ts
@@ -28,7 +28,7 @@ export class NodeDefinition extends Definition {
     this.rules.set(end.fullName, rule)
   }
 
-  getRule(end: NodeDefinition): Rule | undefined {
+  lookupRule(end: NodeDefinition): Rule | undefined {
     return this.rules.get(end.fullName)
   }
 
diff --git a/src/lang/graph/netConnect.ts b/src/lang/graph/netConnect.ts
index 71d8f335..4ac9b849 100644
--- a/src/lang/graph/netConnect.ts
+++ b/src/lang/graph/netConnect.ts
@@ -1,7 +1,7 @@
 import { Action, Net, Port, createEdge } from "../graph"
 
 export function netConnect(net: Net, start: Port, end: Port): void {
-  const rule = net.mod.getRuleByPorts(start, end)
+  const rule = net.mod.lookupRuleByPorts(start, end)
 
   if (rule) {
     net.actions.push(new Action(start, end, rule))
diff --git a/src/lang/mod/Mod.ts b/src/lang/mod/Mod.ts
index ea0e99ce..3e65e827 100644
--- a/src/lang/mod/Mod.ts
+++ b/src/lang/mod/Mod.ts
@@ -13,7 +13,7 @@ export class Mod {
     defineBuiltInOperators(this)
   }
 
-  getDefinitionOrFail(name: string): Definition {
+  lookupDefinitionOrFail(name: string): Definition {
     const definition = this.definitions.get(name)
     if (definition === undefined) {
       throw new Error(`Undefined name: ${name}`)
@@ -22,8 +22,8 @@ export class Mod {
     return definition
   }
 
-  getNodeDefinitionOrFail(name: string): Definitions.NodeDefinition {
-    const definition = this.getDefinitionOrFail(name)
+  lookupNodeDefinitionOrFail(name: string): Definitions.NodeDefinition {
+    const definition = this.lookupDefinitionOrFail(name)
     if (!(definition instanceof Definitions.NodeDefinition)) {
       throw new Error(
         `I expect a node definition, but ${name} is ${definition.constructor.name}`,
@@ -33,8 +33,8 @@ export class Mod {
     return definition
   }
 
-  private getNetDefinitionOrFail(name: string): Definitions.NetDefinition {
-    const definition = this.getDefinitionOrFail(name)
+  private lookupNetDefinitionOrFail(name: string): Definitions.NetDefinition {
+    const definition = this.lookupDefinitionOrFail(name)
     if (!(definition instanceof Definitions.NetDefinition)) {
       throw new Error(
         `I expect a net definition, but ${name} is ${definition.constructor.name}`,
@@ -44,15 +44,15 @@ export class Mod {
     return definition
   }
 
-  getRuleByPorts(start: Port, end: Port): Rule | undefined {
+  lookupRuleByPorts(start: Port, end: Port): Rule | undefined {
     if (start.isPrincipal && end.isPrincipal) {
-      return start.node.definition.getRule(end.node.definition)
+      return start.node.definition.lookupRule(end.node.definition)
     }
   }
 
   buildNet(name: string): Net {
     const net = createNet(this)
-    this.getNetDefinitionOrFail(name).meaning(net)
+    this.lookupNetDefinitionOrFail(name).meaning(net)
     netCleanUpWires(net)
     return net
   }
diff --git a/src/lang/stmts/DefruleStmt.ts b/src/lang/stmts/DefruleStmt.ts
index 4c1dd112..ae25942d 100644
--- a/src/lang/stmts/DefruleStmt.ts
+++ b/src/lang/stmts/DefruleStmt.ts
@@ -15,8 +15,8 @@ export class DefruleStmt extends Stmt {
   }
 
   async execute(mod: Mod): Promise<void> {
-    const startNodeDefinition = mod.getNodeDefinitionOrFail(this.start)
-    const endNodeDefinition = mod.getNodeDefinitionOrFail(this.end)
+    const startNodeDefinition = mod.lookupNodeDefinitionOrFail(this.start)
+    const endNodeDefinition = mod.lookupNodeDefinitionOrFail(this.end)
 
     startNodeDefinition.defineRule(
       endNodeDefinition,
diff --git a/src/lang/words/Call.ts b/src/lang/words/Call.ts
index df71cfb5..21ccacb7 100644
--- a/src/lang/words/Call.ts
+++ b/src/lang/words/Call.ts
@@ -17,7 +17,7 @@ export class Call extends Word {
       net.portStore.delete(this.name)
       net.portStack.push(found)
     } else {
-      mod.getDefinitionOrFail(this.name).meaning(net)
+      mod.lookupDefinitionOrFail(this.name).meaning(net)
     }
   }
 }