13 lines
353 B
Text
13 lines
353 B
Text
open is_equiv
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constants (A B : Type) (f : A → B)
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definition H : is_equiv f := sorry
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definition loop [instance] [h : is_equiv f] : is_equiv f :=
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h
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notation `noinstances` t:max := by with_options [elaborator.ignore_instances true] (exact t)
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example (a : A) : let H' : is_equiv f := H in @(is_equiv.inv f) H' (f a) = a :=
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noinstances (left_inv f a)
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