@@ -16,7 +16,6 @@ import Algebra.Lattice.Properties.BooleanAlgebra as BooleanAlgebraProperties
1616open import Data.Bool.Base
1717 using (Bool; true; false; not; _∧_; _∨_; _xor_ ; if_then_else_; T; _≤_; _<_
1818 ; b≤b; f≤t; f<t)
19- open import Data.Empty using (⊥; ⊥-elim)
2019open import Data.Product.Base using (_×_; _,_; proj₁; proj₂)
2120open import Data.Sum.Base using (_⊎_; inj₁; inj₂; [_,_])
2221open import Function.Base using (_⟨_⟩_; const; id)
@@ -42,6 +41,7 @@ open import Relation.Binary.PropositionalEquality.Properties
4241 using (module ≡-Reasoning ; setoid; decSetoid; isEquivalence)
4342open import Relation.Nullary.Decidable.Core
4443 using (True; yes; no; fromWitness ; toWitness)
44+ open import Relation.Nullary.Negation.Core using (contradiction)
4545import Relation.Unary as U
4646
4747open import Algebra.Definitions {A = Bool} _≡_
@@ -657,10 +657,10 @@ not-¬ {true} refl ()
657657not-¬ {false} refl ()
658658
659659¬-not : ∀ {x y} → x ≢ y → x ≡ not y
660- ¬-not {true} {true} x≢y = ⊥-elim ( x≢y refl)
660+ ¬-not {true} {true} x≢y = contradiction refl x≢y
661661¬-not {true} {false} _ = refl
662662¬-not {false} {true} _ = refl
663- ¬-not {false} {false} x≢y = ⊥-elim ( x≢y refl)
663+ ¬-not {false} {false} x≢y = contradiction refl x≢y
664664
665665------------------------------------------------------------------------
666666-- Properties of _xor_
0 commit comments