English
For a bounded bilinear map b: E × F → G, the derivative within a set u at p equals the derivative h.deriv p, provided a UniqueDiffWithinAt condition holds.
Русский
Для ограниченной билинейной карты b: E × F → G производная внутри множества u в точке p равна h.deriv p, при условии UniqueDiffWithinAt.
LaTeX
$$$fderivWithin 𝕜 b u p = h.deriv(p)$, with $h$ the derivative data and $UniqueDiffWithinAt 𝕜 u p$.$$
Lean4
protected theorem fderivWithin (h : IsBoundedBilinearMap 𝕜 b) (p : E × F) (hxs : UniqueDiffWithinAt 𝕜 u p) :
fderivWithin 𝕜 b u p = h.deriv p :=
by
rw [DifferentiableAt.fderivWithin (h.differentiableAt p) hxs]
exact h.fderiv p