0c15724e8e
The issue was that instantiate_mvars(infer(m)) had a metavariable, while infer(instantiate_mvars(m)) did not. Changing the call from assign to is_def_eq also unifies the type, assigning the metavariable inside the type.
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765 B
Text
23 lines
No EOL
765 B
Text
universes u v
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def equinumerous (α : Type u) (β : Type v) :=
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∃ f : α → β, function.bijective f
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local infix ` ≈ ` := equinumerous
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@[refl] lemma refl {α} : α ≈ α := sorry
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@[trans] lemma trans {α β γ} :
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α ≈ β → β ≈ γ → α ≈ γ := sorry
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@[congr] lemma equinumerous.congr_eqn {α α' β β'} :
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α ≈ α' → β ≈ β' → (α ≈ β) = (α' ≈ β') := sorry
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@[congr] lemma congr_sum {α α' β β'} :
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α ≈ α' → β ≈ β' → (α ⊕ β) ≈ (α' ⊕ β') := sorry
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@[simp] lemma eqn_ulift {α} : ulift α ≈ α := sorry
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@[simp] lemma sum_empty {α} : (α ⊕ empty) ≈ α := sorry
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-- rewriting `ulift empty` ==> `empty` changes the universe level
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example {α : Type u} : (α ⊕ ulift empty) ≈ α := by simp |