diff --git a/rust-semantics/helpers.md b/rust-semantics/helpers.md
index 83d4ef8..ac59498 100644
--- a/rust-semantics/helpers.md
+++ b/rust-semantics/helpers.md
@@ -45,9 +45,6 @@ module RUST-HELPERS
     rule isSignedInt(i16) => true
     rule isSignedInt(i32) => true
     rule isSignedInt(i64) => true
-    rule isSignedInt(i128) => true
-    rule isSignedInt(i160) => true
-    rule isSignedInt(i256) => true
     rule isSignedInt(&T => T)
 
     rule concatNonEmptyStatements(.NonEmptyStatements, S:NonEmptyStatements) => S