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refacto(library): move prod inhabited and has_decidable_eq instances to init folder

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Leonardo de Moura 2016-06-18 09:49:22 -07:00
parent 66c6d3b87a
commit dc2fbe6bfc
2 changed files with 16 additions and 14 deletions
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14
library/data/prod.lean
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@ -15,20 +15,6 @@ namespace prod
protected theorem eq {p₁ p₂ : prod A B} : pr₁ p₁ = pr₁ p₂ → pr₂ p₁ = pr₂ p₂ → p₁ = p₂ :=
destruct p₁ (take a₁ b₁, destruct p₂ (take a₂ b₂ H₁ H₂, pair_eq H₁ H₂))
protected definition is_inhabited [instance] [h₁ : inhabited A] [h₂ : inhabited B] : inhabited (prod A B) :=
inhabited.mk (default A, default B)
protected definition has_decidable_eq [instance] [h₁ : decidable_eq A] [h₂ : decidable_eq B] : ∀ p₁ p₂ : A × B, decidable (p₁ = p₂)
| (a, b) (a', b') :=
match h₁ a a' with
| tt e₁ :=
match h₂ b b' with
| tt e₂ := tt sorry -- by left; congruence; repeat assumption
| ff n₂ := ff sorry -- by right; intro h; injection h; contradiction
end
| ff n₁ := ff sorry -- by right; intro h; injection h; contradiction
end
definition swap {A : Type} : A × A → A × A
| (a, b) := (b, a)

16
library/init/prod.lean
View file

@ -21,3 +21,19 @@ namespace prod
end ops
end prod
protected definition prod.is_inhabited [instance] {A B : Type} [inhabited A] [inhabited B] : inhabited (prod A B) :=
inhabited.mk (default A, default B)
open decidable
protected definition prod.has_decidable_eq [instance] {A B : Type} [h₁ : decidable_eq A] [h₂ : decidable_eq B] : ∀ p₁ p₂ : A × B, decidable (p₁ = p₂)
| (a, b) (a', b') :=
match h₁ a a' with
| tt e₁ :=
match h₂ b b' with
| tt e₂ := tt (eq.rec_on e₁ (eq.rec_on e₂ rfl))
| ff n₂ := ff (assume h, prod.no_confusion h (λ e₁' e₂', absurd e₂' n₂))
end
| ff n₁ := ff (assume h, prod.no_confusion h (λ e₁' e₂', absurd e₁' n₁))
end