fed7ff27e8
https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/Annoying.20LCNF.20errors/near/302056742
27 lines
761 B
Text
27 lines
761 B
Text
namespace MWE
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inductive Id {A : Type u} : A → A → Type u
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| refl {a : A} : Id a a
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attribute [eliminator] Id.casesOn
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infix:50 (priority := high) " = " => Id
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def symm {A : Type u} {a b : A} (p : a = b) : b = a :=
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by { induction p; exact Id.refl }
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def transport {A : Type u} (B : A → Type v) {a b : A} (p : a = b) : B a → B b :=
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by { induction p; exact id }
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def transportconst {A B : Type u} : A = B → A → B :=
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transport id
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def transportconstInv {A B : Type u} (e : A = B) : B → A :=
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transportconst (symm e)
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def transportconstOverInv {A B : Type u} (p : A = B) :
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∀ x, transportconst (symm p) x = transportconstInv p x :=
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by { intro x; apply Id.refl }
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def transportconstInv' {A B : Type u} : A = B → B → A :=
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transportconst ∘ symm
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