34 lines
636 B
Lean4
34 lines
636 B
Lean4
import Game.Tactic.Induction
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import Game.MyNat.Addition
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import Mathlib.Tactic.Have
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import Mathlib.Tactic
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example (a b : ℕ) : a + b = a → b = 0 := by
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induction b with d hd
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· /-
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a : ℕ
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⊢ a + 0 = a → 0 = 0
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-/
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sorry
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· sorry
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example (a b c : ℕ) (g : c = 0) : a + b = a → b = 0 := by
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intro h -- h : a + b = a
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induction b with d hd generalizing g
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· /-
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a b: ℕ
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h✝ : a + b = a
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h : a + 0 = a
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⊢ 0 = 0
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-/
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sorry
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· /-
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case succ
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a c d : ℕ
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hd : c = 0 → a + d = a → d = 0
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g : c = 0
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h : a + MyNat.succ d = a
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⊢ MyNat.succ d = 0
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-/
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sorry
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