matita/matita/tests/elim_pattern.ma

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  14
  15 include "nat/plus.ma".
  16
  17 alias num (instance 0) = "natural number".
  18 lemma ex1: ∀n:nat. n ≠ n+0 → n = O+O → (∀n1.¬¬(n≠n1+O)) → False.
  19  intros (n U V K);
  20  elim n in U:(? (? ? ? %)) ⊢ %;
  21   [ apply (H V)
  22   | apply (K ? H)]
  23 qed.