@@ -4,7 +4,7 @@ import Data.Bool as Bool
44open import Data.Bool.Properties using (∧-comm; ∧-zeroʳ)
55open import Data.Empty using (⊥)
66open import Data.Product as Product using (Σ; _×_; ∃-syntax; _,_)
7- open import Data.Sum as Sum using (_⊎_) renaming ( inj₁ to left ; inj₂ to right )
7+ open import Data.Sum as Sum using (_⊎_; inj₁; inj₂)
88
99open import Relation.Nullary.Negation renaming (¬_ to never)
1010open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl; cong; sym; trans)
@@ -57,12 +57,12 @@ Const' : Prop F → Set
5757Const' p = ∃[ b ] (∀ a → eval p a ≡ b)
5858
5959Const→Const' : ∀ {p} → Const p → Const' p
60- Const→Const' (left taut ) = Bool.true , taut
61- Const→Const' (right contr) = Bool.false , contr
60+ Const→Const' (inj₁ taut ) = Bool.true , taut
61+ Const→Const' (inj₂ contr) = Bool.false , contr
6262
6363Const'→Const : ∀ {p} → Const' p → Const p
64- Const'→Const (Bool.true , taut ) = left taut
65- Const'→Const (Bool.false , contr) = right contr
64+ Const'→Const (Bool.true , taut ) = inj₁ taut
65+ Const'→Const (Bool.false , contr) = inj₂ contr
6666
6767Nonconst : Prop F → Set
6868Nonconst p = Satisfiable p × Falsifiable p
@@ -71,8 +71,8 @@ Nonconst' : Prop F → Set
7171Nonconst' p = never (Const p)
7272
7373Nonconst→Nonconst' : ∀ {p} → Nonconst p → Nonconst' p
74- Nonconst→Nonconst' {p} (_ , (a , a-makes-false)) (left taut) = NonContradiction' p a (taut a) a-makes-false
75- Nonconst→Nonconst' {p} ((a , a-makes-true) , _) (right contr) = NonContradiction' p a a-makes-true (contr a)
74+ Nonconst→Nonconst' {p} (_ , (a , a-makes-false)) (inj₁ taut ) = NonContradiction' p a (taut a) a-makes-false
75+ Nonconst→Nonconst' {p} ((a , a-makes-true) , _) (inj₂ contr) = NonContradiction' p a a-makes-true (contr a)
7676
7777sat-∧ˡ : ∀ p q
7878 → Tautology p
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