Recursion bug

[wilbowma]

This type checks

#lang cur
(require cur/stdlib/prop
         cur/stdlib/sugar
         cur/stdlib/nat
         cur/stdlib/bool)

(:: (λ [n : Nat]
      (match n #:return (== Bool (nat-equal? (plus 1 n) 0) false)
        [z (refl Bool false)]
        [(s n-1) (refl Bool false)]))
    (Π [n : Nat]
       (== Bool (nat-equal? (plus 1 n) 0) false)))

but this one does not:

;; use n+1 instead of 1+n
(:: (λ [n : Nat]
      (match n #:return (== Bool (nat-equal? (plus n 1) 0) false)
        [z (refl Bool false)]
        [(s n-1) (refl Bool false)]))
    (Π [n : Nat]
       (== Bool (nat-equal? (plus n 1) 0) false)))

In the branches, we also know the value of n, so it ought to be able to reduce plus at least 1 step, but for some reason, this doesn't happen.

[wilbowma]

Match is dead; long live match. #55