lean4-htt/tests/lean/run/specialize2.lean at 712d6726e4020dbb37ddd6e9ccda124a9efe741d - max/lean4-htt - maxgit: wireguard access, git repository.

max/lean4-htt

Leonardo de Moura 712d6726e4 feat: rename tactic byCases => by_cases

2022-02-10 17:11:07 -08:00

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 example : (p → q → False) ↔ (¬ p ∨ ¬ q) := by
   apply Iff.intro
   . intro h
     by_cases hp:p <;> by_cases hq:q
     . specialize h hp hq; contradiction
     . exact Or.inr hq
     . exact Or.inl hp
     . exact Or.inr hq
   . intro
     | Or.inl hnp => intros; contradiction
     | Or.inr hnq => intros; contradiction