Files
agdaproofs/Decidable/Lemmas.agda
2020-04-11 12:14:03 +01:00

12 lines
312 B
Agda

{-# OPTIONS --safe --warning=error --without-K #-}
open import LogicalFormulae
open import Decidable.Sets
module Decidable.Lemmas {a : _} {A : Set a} (dec : DecidableSet A) where
squash : {x y : A} .(x y) x y
squash {x} {y} x=y with dec x y
... | inl pr = pr
... | inr bad = exFalso (bad x=y)