exact SetCoe.ext heq
hun : {0, 1} = {0} ∪ {1}
right✝ : ∃ f, Function.Injective f
f : ↑({0} ×ˢ Set.univ) → ℕ
finj : Function.Injective f
g : ↑Set.univ → ↑({0} ×ˢ Set.univ) := fun r => { val := (0, ↑r), property := (_ : (0, ↑r) ∈ {0} ×ˢ Set.univ) }
a b : ↑Set.univ
heq : ↑a = ↑b
⊢ a = b
no goals