30 lines
738 B
Text
30 lines
738 B
Text
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universes u v w
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instance boolToNat : Coe Bool Nat :=
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{ coe := fun b => cond b 1 0 }
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instance natToBool : Coe Nat Bool :=
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{ coe := fun n => match n with
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| 0 => false
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| _ => true }
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structure ConstantFunction (α β : Type) :=
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(f : α → β)
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(h : ∀ a₁ a₂, f a₁ = f a₂)
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instance constantFunctionCoe {α β : Type} : CoeFun (ConstantFunction α β) (fun _ => α → β) :=
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{ coe := fun c => c.f }
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set_option pp.explicit true
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#synth CoeT { x : Nat // x > 0 } ⟨1, sorryAx _⟩ Nat
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#synth CoeT { x : Nat // x > 0 } ⟨1, sorryAx _⟩ Bool
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#synth CoeT Nat 0 (Option Nat)
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#synth CoeT Bool true (Option Nat)
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#synth CoeT Prop (0 = 1) Bool
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#synth CoeT Bool true (Option Nat)
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def f (c : ConstantFunction Nat Nat) : Nat :=
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c 0
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