English
Let F be a fiber functor with a continuous G-action on each fiber. The induced map from G to the automorphism group of F is continuous.
Русский
Пусть F — фибр-функтор с непрерывным действием группы G на каждое волокно. Тогда индуцированная карта из G в группу автоморфизмов F непрерывна.
LaTeX
$$$\mathrm{Continuous}(toAut\,F\,G)$$$
Lean4
theorem toAut_continuous [TopologicalSpace G] [IsTopologicalGroup G] [∀ (X : C), ContinuousSMul G (F.obj X)] :
Continuous (toAut F G) := by
apply continuous_of_continuousAt_one
rw [continuousAt_def, map_one]
intro A hA
obtain ⟨X, _, hX⟩ := ((nhds_one_has_basis_stabilizers F).mem_iff' A).mp hA
rw [mem_nhds_iff]
exact ⟨MulAction.stabilizer G X.pt, Set.preimage_mono (f := toAut F G) hX, stabilizer_isOpen G X.pt, one_mem _⟩