English
For a submersive presentation, the collection {basisDeriv_i} formed by mapping the basis of σ via P.aevalDifferentialEquiv yields a basis of σ → S.
Русский
Для субмассового презентации множество basisDeriv_i образуют базис в пространстве функций σ→S, полученном через P.aevalDifferentialEquiv.
LaTeX
$$$\\text{basisDeriv}(P) = \\text{Basis}_{\\sigma}(S) \\circ P.aevalDifferentialEquiv$$$
Lean4
/-- If `P` is a submersive presentation, the partial derivatives of `P.relation i` by
`P.map j` form a basis of `σ → S`. -/
noncomputable def basisDeriv (P : SubmersivePresentation R S ι σ) : Basis σ S (σ → S) :=
Basis.map (Pi.basisFun S σ) P.aevalDifferentialEquiv