English
The zero section is differentiable as a bundle morphism in the MDifferentiable sense.
Русский
Нулевая секция является дифференцируемым морфизмом расслоения в смысле MDifferentiable.
LaTeX
$$$$MDifferentiable IB (IB.prod 𝓘(\mathbb{k}, F)) (zeroSection F E).$$$$
Lean4
theorem mdifferentiable_zeroSection : MDifferentiable IB (IB.prod 𝓘(𝕜, F)) (zeroSection F E) :=
by
intro x
unfold zeroSection
rw [mdifferentiableAt_section]
apply (mdifferentiableAt_const (c := 0)).congr_of_eventuallyEq
filter_upwards [(trivializationAt F E x).open_baseSet.mem_nhds (mem_baseSet_trivializationAt F E x)] with y hy using
congr_arg Prod.snd <| (trivializationAt F E x).zeroSection 𝕜 hy