23 lines
491 B
Text
23 lines
491 B
Text
import data.int
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open nat int
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variables a b : nat
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variables i j : int
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definition foo := add a i
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definition f₁ := a + i
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example (n : nat) : n + n = 2 * n :=
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begin
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unfold [nat.add,mul],
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apply sorry
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end
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example (n : nat) : n + n = n + n :=
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rfl
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example (a₁ a₂ a₃ : nat) : a₁ = 0 → a₂ = 0 → a₃ = 0 → a₁ + a₂ + a₃ = 0 :=
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assume h₁ h₂ h₃, calc
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a₁ + a₂ + a₃ = 0 + a₂ + a₃ : h₁
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... = 0 + 0 + a₃ : h₂
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... = 0 + 0 + 0 : h₃
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