diff --git a/crates/ailang-check/src/builtins.rs b/crates/ailang-check/src/builtins.rs
index 7997185..e2060bc 100644
--- a/crates/ailang-check/src/builtins.rs
+++ b/crates/ailang-check/src/builtins.rs
@@ -51,7 +51,9 @@ pub fn install(env: &mut crate::Env) {
     // Iter 22-floats.3: arithmetic and comparison ops are polymorphic.
     // Same shape as `==` below — the {Int, Float}-restriction is
     // enforced at codegen, not at typecheck. `%` stays Int-only
-    // (no fmod yet — see spec section A3).
+    // (no fmod yet — `%` semantics for Float require an explicit
+    // decision on sign-of-result and ±0/±Inf edge cases that has
+    // not been made).
     let poly_a_a_to_a = || Type::Forall {
         vars: vec!["a".into()],
         constraints: vec![],
@@ -95,12 +97,15 @@ pub fn install(env: &mut crate::Env) {
         env.globals.insert(op.into(), poly_a_a_to_bool());
     }
 
-    // Iter 16e: `==` is polymorphic — `forall a. (a, a) -> Bool`.
-    // Codegen dispatches on the resolved arg type at the call site:
+    // `==` is polymorphic — `forall a. (a, a) -> Bool`. Codegen
+    // dispatches on the resolved arg type at the call site:
     // `Int` → `icmp eq i64`, `Bool` → `icmp eq i1`, `Str` → `@strcmp`,
-    // `Unit` → constant `i1 1`. ADT/Fn equality is rejected at codegen
-    // with a clear "== not supported for type X" error. The other
-    // comparison ops (`<`, `<=`, `>`, `>=`, `!=`) stay Int-only.
+    // `Unit` → constant `i1 1`, `Float` → `fcmp oeq double`. ADT/Fn
+    // equality is rejected at codegen with a clear "== not supported
+    // for type X" error. The ordering ops (`<`, `<=`, `>`, `>=`, `!=`)
+    // share the same polymorphic shape but with `Bool` return; `==`
+    // stays in its own arm only because the codegen-side dispatch
+    // table has historically been per-op.
     env.globals.insert(
         "==".into(),
         Type::Forall {
@@ -278,8 +283,9 @@ mod tests {
     /// happens in iter 4.
     #[test]
     fn widen_plus_accepts_float_float_float() {
-        let bits = 1.5_f64.to_bits();
-        let ty = synth_in_builtins_env(&app("+", vec![lit_float(bits), lit_float(bits)]));
+        let bits_a = 1.5_f64.to_bits();
+        let bits_b = 2.5_f64.to_bits();
+        let ty = synth_in_builtins_env(&app("+", vec![lit_float(bits_a), lit_float(bits_b)]));
         assert_eq!(ty, Type::float(), "(+ 1.5 2.5) must type as Float");
     }
 
@@ -298,8 +304,9 @@ mod tests {
     /// typecheck cleanly; codegen lowers to `fcmp olt double` in iter 4.
     #[test]
     fn widen_lt_accepts_float_float_bool() {
-        let bits = 1.5_f64.to_bits();
-        let ty = synth_in_builtins_env(&app("<", vec![lit_float(bits), lit_float(bits)]));
-        assert_eq!(ty, Type::bool_(), "(< 1.5 1.5) must type as Bool");
+        let bits_a = 1.5_f64.to_bits();
+        let bits_b = 2.5_f64.to_bits();
+        let ty = synth_in_builtins_env(&app("<", vec![lit_float(bits_a), lit_float(bits_b)]));
+        assert_eq!(ty, Type::bool_(), "(< 1.5 2.5) must type as Bool");
     }
 }