theorem PiBase.Homeomorph.firstCountableTopology {X : Type u_1} {Y : Type u_2} [TopologicalSpace X] [TopologicalSpace Y] [FirstCountableTopology X] (f : X ≃ₜ Y) : FirstCountableTopology Y

theorem PiBase.WellDefined.firstCountableTopology : WellDefined FirstCountableTopology