9 lines
405 B
Text
9 lines
405 B
Text
variables {α₁ : Type} {α₂ : α₁ → Type} {β₁ : Type} {β₂ : β₁ → Type}
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def map (f₁ : α₁ → β₁) (f₂ : Π⦃a⦄, α₂ a → β₂ (f₁ a)) : (Σa, α₂ a) → (Σb, β₂ b)
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| ⟨a₁, a₂⟩ := ⟨f₁ a₁, f₂ a₂⟩
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example (f₁ : α₁ → α₁) (f₂ : Π⦃a⦄, α₂ a → α₂ (f₁ a)) (eq₁ : f₁ = id) : map f₁ f₂ = id :=
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begin
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rw [eq₁],
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end
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