diff --git a/crates/compiler/test_mono/generated/closure_in_list.txt b/crates/compiler/test_mono/generated/closure_in_list.txt
index 62888cb172..231af8da7f 100644
--- a/crates/compiler/test_mono/generated/closure_in_list.txt
+++ b/crates/compiler/test_mono/generated/closure_in_list.txt
@@ -1,6 +1,6 @@
 procedure List.6 (#Attr.2):
-    let List.259 : U64 = lowlevel ListLen #Attr.2;
-    ret List.259;
+    let List.261 : U64 = lowlevel ListLen #Attr.2;
+    ret List.261;
 
 procedure Test.1 (Test.5):
     let Test.2 : I64 = 41i64;
diff --git a/crates/compiler/test_mono/generated/empty_list_of_function_type.txt b/crates/compiler/test_mono/generated/empty_list_of_function_type.txt
index 32ceba4751..8c1377fdf1 100644
--- a/crates/compiler/test_mono/generated/empty_list_of_function_type.txt
+++ b/crates/compiler/test_mono/generated/empty_list_of_function_type.txt
@@ -1,22 +1,22 @@
-procedure List.2 (List.73, List.74):
-    let List.265 : U64 = CallByName List.6 List.73;
-    let List.261 : Int1 = CallByName Num.22 List.74 List.265;
-    if List.261 then
-        let List.263 : {} = CallByName List.60 List.73 List.74;
-        let List.262 : [C {}, C {}] = Ok List.263;
-        ret List.262;
+procedure List.2 (List.74, List.75):
+    let List.267 : U64 = CallByName List.6 List.74;
+    let List.263 : Int1 = CallByName Num.22 List.75 List.267;
+    if List.263 then
+        let List.265 : {} = CallByName List.60 List.74 List.75;
+        let List.264 : [C {}, C {}] = Ok List.265;
+        ret List.264;
     else
-        let List.260 : {} = Struct {};
-        let List.259 : [C {}, C {}] = Err List.260;
-        ret List.259;
+        let List.262 : {} = Struct {};
+        let List.261 : [C {}, C {}] = Err List.262;
+        ret List.261;
 
 procedure List.6 (#Attr.2):
-    let List.268 : U64 = lowlevel ListLen #Attr.2;
-    ret List.268;
+    let List.270 : U64 = lowlevel ListLen #Attr.2;
+    ret List.270;
 
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.267 : {} = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.267;
+    let List.269 : {} = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.269;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.273 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/encode.txt b/crates/compiler/test_mono/generated/encode.txt
index 24f2d236f3..36f83213af 100644
--- a/crates/compiler/test_mono/generated/encode.txt
+++ b/crates/compiler/test_mono/generated/encode.txt
@@ -1,6 +1,6 @@
 procedure List.4 (#Attr.2, #Attr.3):
-    let List.259 : List U8 = lowlevel ListAppend #Attr.2 #Attr.3;
-    ret List.259;
+    let List.261 : List U8 = lowlevel ListAppend #Attr.2 #Attr.3;
+    ret List.261;
 
 procedure Test.20 (Test.22):
     let Test.34 : {U8} = Struct {Test.22};
diff --git a/crates/compiler/test_mono/generated/ir_int_add.txt b/crates/compiler/test_mono/generated/ir_int_add.txt
index f253209877..b620b23320 100644
--- a/crates/compiler/test_mono/generated/ir_int_add.txt
+++ b/crates/compiler/test_mono/generated/ir_int_add.txt
@@ -1,6 +1,6 @@
 procedure List.6 (#Attr.2):
-    let List.259 : U64 = lowlevel ListLen #Attr.2;
-    ret List.259;
+    let List.261 : U64 = lowlevel ListLen #Attr.2;
+    ret List.261;
 
 procedure Num.19 (#Attr.2, #Attr.3):
     let Num.275 : U64 = lowlevel NumAdd #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/issue_2583_specialize_errors_behind_unified_branches.txt b/crates/compiler/test_mono/generated/issue_2583_specialize_errors_behind_unified_branches.txt
index b9b7329502..4cf882f173 100644
--- a/crates/compiler/test_mono/generated/issue_2583_specialize_errors_behind_unified_branches.txt
+++ b/crates/compiler/test_mono/generated/issue_2583_specialize_errors_behind_unified_branches.txt
@@ -1,37 +1,37 @@
-procedure List.2 (List.73, List.74):
-    let List.274 : U64 = CallByName List.6 List.73;
-    let List.270 : Int1 = CallByName Num.22 List.74 List.274;
-    if List.270 then
-        let List.272 : I64 = CallByName List.60 List.73 List.74;
-        let List.271 : [C {}, C I64] = Ok List.272;
-        ret List.271;
+procedure List.2 (List.74, List.75):
+    let List.276 : U64 = CallByName List.6 List.74;
+    let List.272 : Int1 = CallByName Num.22 List.75 List.276;
+    if List.272 then
+        let List.274 : I64 = CallByName List.60 List.74 List.75;
+        let List.273 : [C {}, C I64] = Ok List.274;
+        ret List.273;
     else
-        let List.269 : {} = Struct {};
-        let List.268 : [C {}, C I64] = Err List.269;
-        ret List.268;
+        let List.271 : {} = Struct {};
+        let List.270 : [C {}, C I64] = Err List.271;
+        ret List.270;
 
 procedure List.6 (#Attr.2):
-    let List.275 : U64 = lowlevel ListLen #Attr.2;
-    ret List.275;
+    let List.277 : U64 = lowlevel ListLen #Attr.2;
+    ret List.277;
 
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.273 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.273;
+    let List.275 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.275;
 
-procedure List.9 (List.184):
-    let List.266 : U64 = 0i64;
-    let List.259 : [C {}, C I64] = CallByName List.2 List.184 List.266;
-    let List.263 : U8 = 1i64;
-    let List.264 : U8 = GetTagId List.259;
-    let List.265 : Int1 = lowlevel Eq List.263 List.264;
-    if List.265 then
-        let List.185 : I64 = UnionAtIndex (Id 1) (Index 0) List.259;
-        let List.260 : [C Int1, C I64] = Ok List.185;
-        ret List.260;
+procedure List.9 (List.185):
+    let List.268 : U64 = 0i64;
+    let List.261 : [C {}, C I64] = CallByName List.2 List.185 List.268;
+    let List.265 : U8 = 1i64;
+    let List.266 : U8 = GetTagId List.261;
+    let List.267 : Int1 = lowlevel Eq List.265 List.266;
+    if List.267 then
+        let List.186 : I64 = UnionAtIndex (Id 1) (Index 0) List.261;
+        let List.262 : [C Int1, C I64] = Ok List.186;
+        ret List.262;
     else
-        let List.262 : Int1 = true;
-        let List.261 : [C Int1, C I64] = Err List.262;
-        ret List.261;
+        let List.264 : Int1 = true;
+        let List.263 : [C Int1, C I64] = Err List.264;
+        ret List.263;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.273 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_append.txt b/crates/compiler/test_mono/generated/list_append.txt
index d1ee6edc79..d7b825ab89 100644
--- a/crates/compiler/test_mono/generated/list_append.txt
+++ b/crates/compiler/test_mono/generated/list_append.txt
@@ -1,6 +1,6 @@
 procedure List.4 (#Attr.2, #Attr.3):
-    let List.259 : List I64 = lowlevel ListAppend #Attr.2 #Attr.3;
-    ret List.259;
+    let List.261 : List I64 = lowlevel ListAppend #Attr.2 #Attr.3;
+    ret List.261;
 
 procedure Test.0 ():
     let Test.2 : List I64 = Array [1i64];
diff --git a/crates/compiler/test_mono/generated/list_append_closure.txt b/crates/compiler/test_mono/generated/list_append_closure.txt
index f8082a8cba..f8fc47a912 100644
--- a/crates/compiler/test_mono/generated/list_append_closure.txt
+++ b/crates/compiler/test_mono/generated/list_append_closure.txt
@@ -1,6 +1,6 @@
 procedure List.4 (#Attr.2, #Attr.3):
-    let List.259 : List I64 = lowlevel ListAppend #Attr.2 #Attr.3;
-    ret List.259;
+    let List.261 : List I64 = lowlevel ListAppend #Attr.2 #Attr.3;
+    ret List.261;
 
 procedure Test.1 (Test.2):
     let Test.6 : I64 = 42i64;
diff --git a/crates/compiler/test_mono/generated/list_cannot_update_inplace.txt b/crates/compiler/test_mono/generated/list_cannot_update_inplace.txt
index b16f784fd5..6696b0d28d 100644
--- a/crates/compiler/test_mono/generated/list_cannot_update_inplace.txt
+++ b/crates/compiler/test_mono/generated/list_cannot_update_inplace.txt
@@ -1,27 +1,27 @@
-procedure List.3 (List.82, List.83, List.84):
-    let List.262 : {List I64, I64} = CallByName List.57 List.82 List.83 List.84;
-    let List.261 : List I64 = StructAtIndex 0 List.262;
-    inc List.261;
-    dec List.262;
-    ret List.261;
+procedure List.3 (List.83, List.84, List.85):
+    let List.264 : {List I64, I64} = CallByName List.57 List.83 List.84 List.85;
+    let List.263 : List I64 = StructAtIndex 0 List.264;
+    inc List.263;
+    dec List.264;
+    ret List.263;
 
-procedure List.57 (List.79, List.80, List.81):
-    let List.268 : U64 = CallByName List.6 List.79;
-    let List.265 : Int1 = CallByName Num.22 List.80 List.268;
-    if List.265 then
-        let List.266 : {List I64, I64} = CallByName List.61 List.79 List.80 List.81;
-        ret List.266;
+procedure List.57 (List.80, List.81, List.82):
+    let List.270 : U64 = CallByName List.6 List.80;
+    let List.267 : Int1 = CallByName Num.22 List.81 List.270;
+    if List.267 then
+        let List.268 : {List I64, I64} = CallByName List.61 List.80 List.81 List.82;
+        ret List.268;
     else
-        let List.264 : {List I64, I64} = Struct {List.79, List.81};
-        ret List.264;
+        let List.266 : {List I64, I64} = Struct {List.80, List.82};
+        ret List.266;
 
 procedure List.6 (#Attr.2):
-    let List.260 : U64 = lowlevel ListLen #Attr.2;
-    ret List.260;
+    let List.262 : U64 = lowlevel ListLen #Attr.2;
+    ret List.262;
 
 procedure List.61 (#Attr.2, #Attr.3, #Attr.4):
-    let List.267 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
-    ret List.267;
+    let List.269 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
+    ret List.269;
 
 procedure Num.19 (#Attr.2, #Attr.3):
     let Num.273 : U64 = lowlevel NumAdd #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_get.txt b/crates/compiler/test_mono/generated/list_get.txt
index 90b029963d..e2ae0a2e02 100644
--- a/crates/compiler/test_mono/generated/list_get.txt
+++ b/crates/compiler/test_mono/generated/list_get.txt
@@ -1,22 +1,22 @@
-procedure List.2 (List.73, List.74):
-    let List.265 : U64 = CallByName List.6 List.73;
-    let List.261 : Int1 = CallByName Num.22 List.74 List.265;
-    if List.261 then
-        let List.263 : I64 = CallByName List.60 List.73 List.74;
-        let List.262 : [C {}, C I64] = Ok List.263;
-        ret List.262;
+procedure List.2 (List.74, List.75):
+    let List.267 : U64 = CallByName List.6 List.74;
+    let List.263 : Int1 = CallByName Num.22 List.75 List.267;
+    if List.263 then
+        let List.265 : I64 = CallByName List.60 List.74 List.75;
+        let List.264 : [C {}, C I64] = Ok List.265;
+        ret List.264;
     else
-        let List.260 : {} = Struct {};
-        let List.259 : [C {}, C I64] = Err List.260;
-        ret List.259;
+        let List.262 : {} = Struct {};
+        let List.261 : [C {}, C I64] = Err List.262;
+        ret List.261;
 
 procedure List.6 (#Attr.2):
-    let List.268 : U64 = lowlevel ListLen #Attr.2;
-    ret List.268;
+    let List.270 : U64 = lowlevel ListLen #Attr.2;
+    ret List.270;
 
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.267 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.267;
+    let List.269 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.269;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.273 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_len.txt b/crates/compiler/test_mono/generated/list_len.txt
index 88f96ee477..aec72c7161 100644
--- a/crates/compiler/test_mono/generated/list_len.txt
+++ b/crates/compiler/test_mono/generated/list_len.txt
@@ -1,10 +1,10 @@
 procedure List.6 (#Attr.2):
-    let List.259 : U64 = lowlevel ListLen #Attr.2;
-    ret List.259;
+    let List.261 : U64 = lowlevel ListLen #Attr.2;
+    ret List.261;
 
 procedure List.6 (#Attr.2):
-    let List.260 : U64 = lowlevel ListLen #Attr.2;
-    ret List.260;
+    let List.262 : U64 = lowlevel ListLen #Attr.2;
+    ret List.262;
 
 procedure Num.19 (#Attr.2, #Attr.3):
     let Num.273 : U64 = lowlevel NumAdd #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_map_closure_borrows.txt b/crates/compiler/test_mono/generated/list_map_closure_borrows.txt
index 6c36130b53..db6b764958 100644
--- a/crates/compiler/test_mono/generated/list_map_closure_borrows.txt
+++ b/crates/compiler/test_mono/generated/list_map_closure_borrows.txt
@@ -1,26 +1,26 @@
-procedure List.2 (List.73, List.74):
-    let List.265 : U64 = CallByName List.6 List.73;
-    let List.261 : Int1 = CallByName Num.22 List.74 List.265;
-    if List.261 then
-        let List.263 : Str = CallByName List.60 List.73 List.74;
-        let List.262 : [C {}, C Str] = Ok List.263;
-        ret List.262;
+procedure List.2 (List.74, List.75):
+    let List.267 : U64 = CallByName List.6 List.74;
+    let List.263 : Int1 = CallByName Num.22 List.75 List.267;
+    if List.263 then
+        let List.265 : Str = CallByName List.60 List.74 List.75;
+        let List.264 : [C {}, C Str] = Ok List.265;
+        ret List.264;
     else
-        let List.260 : {} = Struct {};
-        let List.259 : [C {}, C Str] = Err List.260;
-        ret List.259;
+        let List.262 : {} = Struct {};
+        let List.261 : [C {}, C Str] = Err List.262;
+        ret List.261;
 
 procedure List.5 (#Attr.2, #Attr.3):
-    let List.267 : List Str = lowlevel ListMap { xs: `#Attr.#arg1` } #Attr.2 Test.3 #Attr.3;
-    ret List.267;
-
-procedure List.6 (#Attr.2):
-    let List.269 : U64 = lowlevel ListLen #Attr.2;
+    let List.269 : List Str = lowlevel ListMap { xs: `#Attr.#arg1` } #Attr.2 Test.3 #Attr.3;
     ret List.269;
 
+procedure List.6 (#Attr.2):
+    let List.271 : U64 = lowlevel ListLen #Attr.2;
+    ret List.271;
+
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.268 : Str = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.268;
+    let List.270 : Str = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.270;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.273 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_map_closure_owns.txt b/crates/compiler/test_mono/generated/list_map_closure_owns.txt
index cb871765d1..2ff1471282 100644
--- a/crates/compiler/test_mono/generated/list_map_closure_owns.txt
+++ b/crates/compiler/test_mono/generated/list_map_closure_owns.txt
@@ -1,28 +1,28 @@
-procedure List.2 (List.73, List.74):
-    let List.265 : U64 = CallByName List.6 List.73;
-    let List.261 : Int1 = CallByName Num.22 List.74 List.265;
-    if List.261 then
-        let List.263 : Str = CallByName List.60 List.73 List.74;
-        let List.262 : [C {}, C Str] = Ok List.263;
-        ret List.262;
+procedure List.2 (List.74, List.75):
+    let List.267 : U64 = CallByName List.6 List.74;
+    let List.263 : Int1 = CallByName Num.22 List.75 List.267;
+    if List.263 then
+        let List.265 : Str = CallByName List.60 List.74 List.75;
+        let List.264 : [C {}, C Str] = Ok List.265;
+        ret List.264;
     else
-        let List.260 : {} = Struct {};
-        let List.259 : [C {}, C Str] = Err List.260;
-        ret List.259;
+        let List.262 : {} = Struct {};
+        let List.261 : [C {}, C Str] = Err List.262;
+        ret List.261;
 
 procedure List.5 (#Attr.2, #Attr.3):
     inc #Attr.2;
-    let List.267 : List Str = lowlevel ListMap { xs: `#Attr.#arg1` } #Attr.2 Test.3 #Attr.3;
+    let List.269 : List Str = lowlevel ListMap { xs: `#Attr.#arg1` } #Attr.2 Test.3 #Attr.3;
     decref #Attr.2;
-    ret List.267;
-
-procedure List.6 (#Attr.2):
-    let List.269 : U64 = lowlevel ListLen #Attr.2;
     ret List.269;
 
+procedure List.6 (#Attr.2):
+    let List.271 : U64 = lowlevel ListLen #Attr.2;
+    ret List.271;
+
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.268 : Str = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.268;
+    let List.270 : Str = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.270;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.273 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_pass_to_function.txt b/crates/compiler/test_mono/generated/list_pass_to_function.txt
index 5389fc1469..07b1cfdb32 100644
--- a/crates/compiler/test_mono/generated/list_pass_to_function.txt
+++ b/crates/compiler/test_mono/generated/list_pass_to_function.txt
@@ -1,27 +1,27 @@
-procedure List.3 (List.82, List.83, List.84):
-    let List.260 : {List I64, I64} = CallByName List.57 List.82 List.83 List.84;
-    let List.259 : List I64 = StructAtIndex 0 List.260;
-    inc List.259;
-    dec List.260;
-    ret List.259;
+procedure List.3 (List.83, List.84, List.85):
+    let List.262 : {List I64, I64} = CallByName List.57 List.83 List.84 List.85;
+    let List.261 : List I64 = StructAtIndex 0 List.262;
+    inc List.261;
+    dec List.262;
+    ret List.261;
 
-procedure List.57 (List.79, List.80, List.81):
-    let List.266 : U64 = CallByName List.6 List.79;
-    let List.263 : Int1 = CallByName Num.22 List.80 List.266;
-    if List.263 then
-        let List.264 : {List I64, I64} = CallByName List.61 List.79 List.80 List.81;
-        ret List.264;
+procedure List.57 (List.80, List.81, List.82):
+    let List.268 : U64 = CallByName List.6 List.80;
+    let List.265 : Int1 = CallByName Num.22 List.81 List.268;
+    if List.265 then
+        let List.266 : {List I64, I64} = CallByName List.61 List.80 List.81 List.82;
+        ret List.266;
     else
-        let List.262 : {List I64, I64} = Struct {List.79, List.81};
-        ret List.262;
+        let List.264 : {List I64, I64} = Struct {List.80, List.82};
+        ret List.264;
 
 procedure List.6 (#Attr.2):
-    let List.267 : U64 = lowlevel ListLen #Attr.2;
-    ret List.267;
+    let List.269 : U64 = lowlevel ListLen #Attr.2;
+    ret List.269;
 
 procedure List.61 (#Attr.2, #Attr.3, #Attr.4):
-    let List.265 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
-    ret List.265;
+    let List.267 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
+    ret List.267;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.273 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/list_sort_asc.txt b/crates/compiler/test_mono/generated/list_sort_asc.txt
index e9da864802..940731a416 100644
--- a/crates/compiler/test_mono/generated/list_sort_asc.txt
+++ b/crates/compiler/test_mono/generated/list_sort_asc.txt
@@ -1,16 +1,16 @@
 procedure List.28 (#Attr.2, #Attr.3):
-    let List.262 : List I64 = lowlevel ListSortWith { xs: `#Attr.#arg1` } #Attr.2 Num.46 #Attr.3;
+    let List.264 : List I64 = lowlevel ListSortWith { xs: `#Attr.#arg1` } #Attr.2 Num.46 #Attr.3;
     let Bool.14 : Int1 = lowlevel ListIsUnique #Attr.2;
     if Bool.14 then
-        ret List.262;
+        ret List.264;
     else
         decref #Attr.2;
-        ret List.262;
+        ret List.264;
 
-procedure List.54 (List.178):
-    let List.260 : {} = Struct {};
-    let List.259 : List I64 = CallByName List.28 List.178 List.260;
-    ret List.259;
+procedure List.54 (List.179):
+    let List.262 : {} = Struct {};
+    let List.261 : List I64 = CallByName List.28 List.179 List.262;
+    ret List.261;
 
 procedure Num.46 (#Attr.2, #Attr.3):
     let Num.273 : U8 = lowlevel NumCompare #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/quicksort_swap.txt b/crates/compiler/test_mono/generated/quicksort_swap.txt
index 68cafdd152..66581e9c95 100644
--- a/crates/compiler/test_mono/generated/quicksort_swap.txt
+++ b/crates/compiler/test_mono/generated/quicksort_swap.txt
@@ -1,43 +1,43 @@
-procedure List.2 (List.73, List.74):
-    let List.279 : U64 = CallByName List.6 List.73;
-    let List.275 : Int1 = CallByName Num.22 List.74 List.279;
-    if List.275 then
-        let List.277 : I64 = CallByName List.60 List.73 List.74;
-        let List.276 : [C {}, C I64] = Ok List.277;
-        ret List.276;
+procedure List.2 (List.74, List.75):
+    let List.281 : U64 = CallByName List.6 List.74;
+    let List.277 : Int1 = CallByName Num.22 List.75 List.281;
+    if List.277 then
+        let List.279 : I64 = CallByName List.60 List.74 List.75;
+        let List.278 : [C {}, C I64] = Ok List.279;
+        ret List.278;
     else
-        let List.274 : {} = Struct {};
-        let List.273 : [C {}, C I64] = Err List.274;
-        ret List.273;
+        let List.276 : {} = Struct {};
+        let List.275 : [C {}, C I64] = Err List.276;
+        ret List.275;
 
-procedure List.3 (List.82, List.83, List.84):
-    let List.263 : {List I64, I64} = CallByName List.57 List.82 List.83 List.84;
-    let List.262 : List I64 = StructAtIndex 0 List.263;
-    inc List.262;
-    dec List.263;
-    ret List.262;
+procedure List.3 (List.83, List.84, List.85):
+    let List.265 : {List I64, I64} = CallByName List.57 List.83 List.84 List.85;
+    let List.264 : List I64 = StructAtIndex 0 List.265;
+    inc List.264;
+    dec List.265;
+    ret List.264;
 
-procedure List.57 (List.79, List.80, List.81):
-    let List.285 : U64 = CallByName List.6 List.79;
-    let List.282 : Int1 = CallByName Num.22 List.80 List.285;
-    if List.282 then
-        let List.283 : {List I64, I64} = CallByName List.61 List.79 List.80 List.81;
+procedure List.57 (List.80, List.81, List.82):
+    let List.287 : U64 = CallByName List.6 List.80;
+    let List.284 : Int1 = CallByName Num.22 List.81 List.287;
+    if List.284 then
+        let List.285 : {List I64, I64} = CallByName List.61 List.80 List.81 List.82;
+        ret List.285;
+    else
+        let List.283 : {List I64, I64} = Struct {List.80, List.82};
         ret List.283;
-    else
-        let List.281 : {List I64, I64} = Struct {List.79, List.81};
-        ret List.281;
 
 procedure List.6 (#Attr.2):
-    let List.286 : U64 = lowlevel ListLen #Attr.2;
-    ret List.286;
+    let List.288 : U64 = lowlevel ListLen #Attr.2;
+    ret List.288;
 
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.287 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.287;
+    let List.289 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.289;
 
 procedure List.61 (#Attr.2, #Attr.3, #Attr.4):
-    let List.284 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
-    ret List.284;
+    let List.286 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
+    ret List.286;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.275 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;
diff --git a/crates/compiler/test_mono/generated/rigids.txt b/crates/compiler/test_mono/generated/rigids.txt
index 4c970a9027..fb2b39bacf 100644
--- a/crates/compiler/test_mono/generated/rigids.txt
+++ b/crates/compiler/test_mono/generated/rigids.txt
@@ -1,43 +1,43 @@
-procedure List.2 (List.73, List.74):
-    let List.279 : U64 = CallByName List.6 List.73;
-    let List.275 : Int1 = CallByName Num.22 List.74 List.279;
-    if List.275 then
-        let List.277 : I64 = CallByName List.60 List.73 List.74;
-        let List.276 : [C {}, C I64] = Ok List.277;
-        ret List.276;
+procedure List.2 (List.74, List.75):
+    let List.281 : U64 = CallByName List.6 List.74;
+    let List.277 : Int1 = CallByName Num.22 List.75 List.281;
+    if List.277 then
+        let List.279 : I64 = CallByName List.60 List.74 List.75;
+        let List.278 : [C {}, C I64] = Ok List.279;
+        ret List.278;
     else
-        let List.274 : {} = Struct {};
-        let List.273 : [C {}, C I64] = Err List.274;
-        ret List.273;
+        let List.276 : {} = Struct {};
+        let List.275 : [C {}, C I64] = Err List.276;
+        ret List.275;
 
-procedure List.3 (List.82, List.83, List.84):
-    let List.263 : {List I64, I64} = CallByName List.57 List.82 List.83 List.84;
-    let List.262 : List I64 = StructAtIndex 0 List.263;
-    inc List.262;
-    dec List.263;
-    ret List.262;
+procedure List.3 (List.83, List.84, List.85):
+    let List.265 : {List I64, I64} = CallByName List.57 List.83 List.84 List.85;
+    let List.264 : List I64 = StructAtIndex 0 List.265;
+    inc List.264;
+    dec List.265;
+    ret List.264;
 
-procedure List.57 (List.79, List.80, List.81):
-    let List.285 : U64 = CallByName List.6 List.79;
-    let List.282 : Int1 = CallByName Num.22 List.80 List.285;
-    if List.282 then
-        let List.283 : {List I64, I64} = CallByName List.61 List.79 List.80 List.81;
+procedure List.57 (List.80, List.81, List.82):
+    let List.287 : U64 = CallByName List.6 List.80;
+    let List.284 : Int1 = CallByName Num.22 List.81 List.287;
+    if List.284 then
+        let List.285 : {List I64, I64} = CallByName List.61 List.80 List.81 List.82;
+        ret List.285;
+    else
+        let List.283 : {List I64, I64} = Struct {List.80, List.82};
         ret List.283;
-    else
-        let List.281 : {List I64, I64} = Struct {List.79, List.81};
-        ret List.281;
 
 procedure List.6 (#Attr.2):
-    let List.286 : U64 = lowlevel ListLen #Attr.2;
-    ret List.286;
+    let List.288 : U64 = lowlevel ListLen #Attr.2;
+    ret List.288;
 
 procedure List.60 (#Attr.2, #Attr.3):
-    let List.287 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
-    ret List.287;
+    let List.289 : I64 = lowlevel ListGetUnsafe #Attr.2 #Attr.3;
+    ret List.289;
 
 procedure List.61 (#Attr.2, #Attr.3, #Attr.4):
-    let List.284 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
-    ret List.284;
+    let List.286 : {List I64, I64} = lowlevel ListReplaceUnsafe #Attr.2 #Attr.3 #Attr.4;
+    ret List.286;
 
 procedure Num.22 (#Attr.2, #Attr.3):
     let Num.275 : Int1 = lowlevel NumLt #Attr.2 #Attr.3;