∀ {B : Type u_1} {F : Type u_2} {Z : Type u_4} [inst : TopologicalSpace B] [inst_1 : TopologicalSpace F] {proj : Z → B}
  [inst_2 : TopologicalSpace Z] (e : Trivialization F proj) {z : Z},
  z ∈ e.source → nhds z = Filter.comap proj (nhds (proj z)) ⊓ Filter.comap (Prod.snd ∘ ↑e) (nhds (↑e z).2)