16 lines
551 B
Text
16 lines
551 B
Text
theorem eq_iff_true_of_subsingleton [Subsingleton α] (x y : α) : x = y ↔ True :=
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⟨fun _ => ⟨⟩, fun _ => (Subsingleton.elim ..)⟩
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attribute [simp] eq_iff_true_of_subsingleton in
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example : True := trivial
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structure Func' (α : Sort _) (β : Sort _) :=
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(toFun : α → β)
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def r : Func' α α := ⟨id⟩
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@[simp] theorem r_toFun {α : Sort u_1} (a : α) : Func'.toFun r a = id a := rfl
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example (x y : α) (h : x = y) : r.toFun x = y := by simp <;> rw [h]
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theorem noissue (x y : α) (h : x = y) : r.toFun x = y := by simp <;> rw [h]
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