∀ {ι : Type u_3} {B : Type u_1} {F : Type u_2} [inst : TopologicalSpace B] [inst_1 : TopologicalSpace F]
  (Z : FiberBundleCore ι B F) (i : ι) (p : Z.TotalSpace),
  (↑{ toPartialEquiv := Z.localTrivAsPartialEquiv i, open_source := ⋯, open_target := ⋯, continuousOn_toFun := ⋯,
            continuousOn_invFun := ⋯ }
        p).1 =
    Z.proj p