theorem instCoeDepTypeDaughterOfIs._proof_1
theorem instCoeDepTypeDaughterOfIs._proof_1: ∀ (x : Type) [qxpdv9xr.Daughter.Is x], qxpdv9xr.Daughter.Is x
theorem instCoeDepTypeDaughterOfIs._proof_1
theorem instCoeDepTypeDaughterOfIs._proof_1: ∀ (x : Type) [qxpdv9xr.Daughter.Is x], qxpdv9xr.Daughter.Is x