(module print_eq_arg_repro
  (fn main
    (doc "RED-pin fixture for the iter 24.3 cursor-misalignment bug. `(app print <arg>)` where `<arg>` itself contains a class-method call (here `eq`) causes the mono-rewrite cursor to consume the `Show T` residual pushed by `print`'s poly-free-fn observation as if it were the slot for the inner class method. Result: the inner `eq` Var is rewritten to `prelude.show__Bool` instead of `prelude.eq__Int`, and codegen reports `call prelude.show__Bool arg type mismatch: expected i1, got i64`. Bug surfaced 2026-05-14 during the rpe.1 BLOCKED orchestrator run; root cause is `crates/ailang-check/src/mono.rs::interleave_slots` not advancing the class-residual cursor when visiting a poly-free-fn Var whose source `Type::Forall` carries a class constraint. Fixture pinned by `print_with_class_method_arg_does_not_misalign_mono_cursor` in crates/ail/tests/show_print_e2e.rs.")
    (type (fn-type (params) (ret (own (con Unit))) (effects IO)))
    (params)
    (body (app print (app eq 1 2)))))