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feat(library/init/logic): add new simp rules

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Leonardo de Moura 2015-11-22 17:04:25 -08:00
parent 56282a11f6
commit d240b06ba2
1 changed files with 11 additions and 0 deletions
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11
library/init/logic.lean
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@ -361,6 +361,11 @@ iff_false_intro (λ H,
have H' : ¬a, from (λ Ha, (iff.mp H Ha) Ha),
H' (iff.mpr H H'))
theorem not_iff_self [simp] (a : Prop) : (¬a ↔ a) ↔ false :=
iff_false_intro (λ H,
have H' : ¬a, from (λ Ha, (iff.mpr H Ha) Ha),
H' (iff.mp H H'))
theorem true_iff_false [simp] : (true ↔ false) ↔ false :=
iff_false_intro (λ H, iff.mp H trivial)
@ -406,6 +411,12 @@ iff_false_intro and.right
theorem false_and [simp] (a : Prop) : false ∧ a ↔ false :=
iff_false_intro and.left
theorem not_and_self [simp] (a : Prop) : (¬a ∧ a) ↔ false :=
iff_false_intro (λ H, and.elim H (λ H₁ H₂, absurd H₂ H₁))
theorem and_not_self [simp] (a : Prop) : (a ∧ ¬a) ↔ false :=
iff_false_intro (λ H, and.elim H (λ H₁ H₂, absurd H₁ H₂))
theorem and_self [simp] (a : Prop) : a ∧ a ↔ a :=
iff.intro and.left (assume H, and.intro H H)