10 lines
239 B
Text
10 lines
239 B
Text
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constants {A B : Type} {P : B → Type} {f : A → B}
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(rec_on : Π(b : B) (H : Πa, P (f a)) (H2 : Πa, H a = H a), P b)
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example (b : B) (H : Πa, P (f a)) : P b :=
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begin
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fapply (rec_on b),
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{exact H},
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{clear b, apply sorry}
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end
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