Function cheap_beta_overapplied_appends_remaining

crates/kernel/src/subst.rs:1269–1281

()

    // Inside the lambda, Var(0) is still bound, Var(1) becomes fv0.
    let expected = AE::lam((), (), nat, AE::app(AE::var(0, ()), fv0));
    assert_eq!(result, expected);
  }

  // ---- abstract_fvars ----

  #[test]
  fn abstract_fvars_empty_passthrough() {
    let mut env = InternTable::<Anon>::new();
    let v0 = AE::var(0, ());
    let result = abstract_fvars(&mut env, &v0, &[]);
    assert!(result.ptr_eq(&v0));
  }

  #[test]
  fn abstract_fvars_no_fvars_shifts_loose_bvar() {
    let mut env = InternTable::<Anon>::new();