26 lines
526 B
Text
26 lines
526 B
Text
theorem ex1 (n : Nat) : 0 + n = n := by
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let m := n
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have h : ∃ k, id k = m := ⟨m, rfl⟩
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cases h with
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| intro a e =>
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traceState
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subst e
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traceState
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apply Nat.zero_add
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theorem ex2 (n : Nat) : 0 + n = n := by
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let m := n
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have h : ∃ k, m = id k := ⟨m, rfl⟩
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cases h with
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| intro a e =>
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traceState
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subst e
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traceState
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apply Nat.zero_add
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theorem ex3 (n : Nat) (h : n = 0) : 0 + n = 0 := by
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let m := n + 1
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let v := m + 1
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have : v = n + 2 := rfl
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subst v -- error
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done
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