24 lines
427 B
Lean4
24 lines
427 B
Lean4
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import Mathlib
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-- Theorem: For any natural number n, n + 0 = n.
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theorem demo (n : ℕ) : n + 0 = n := by
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/- <feedback>
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-- proof state:
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n : ℕ
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⊢ n + 0 = n
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</feedback> -/
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induction n with
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/- <feedback>
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-- proof state:
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case zero
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⊢ 0 + 0 = 0
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</feedback> -/
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| zero => rfl
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/- <feedback>
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-- proof state:
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ih : n + 0 = n
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case succ
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⊢ n + 1 + 0 = n + 1
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</feedback> -/
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| succ n ih => simp_all
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