9 lines
314 B
Text
9 lines
314 B
Text
def casesTFOn {motive : Prop → Sort _} (P) [inst : Decidable P] : (T : motive True) → (F : motive False) → motive P :=
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λ ht hf => match inst with
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| isTrue H => eqTrue H ▸ ht
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| isFalse H => eqFalse H ▸ hf
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example (P) [Decidable P] : ¬¬P → P := by
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induction P using casesTFOn
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admit
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admit
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