message: Avoid adding extraneous type annotations
diff: @@ -1054,6 +1054,10 @@ pub mod distillation {
  pub fn check(&mut self, core_term: &core::Term<'_>) -> surface::Term<'arena> {
  match core_term {
  + core::Term::Ann(expr, _) => {
  + // Avoid adding extraneous type annotations!
  + self.check(expr)
  + }
  core::Term::Let(def_name, def_expr, body_expr) => {
  let (def_expr, def_type) = match self.synth(def_expr) {
  surface::Term::Ann(expr, r#type) => (expr, Some(r#type)),
  