English
For a finite basis b, B.flip.dualSubmodule (B.dualSubmodule (span_R(range b))) = span_R(range b).
Русский
Для базиса b: B.flip.dualSubmodule(B.dualSubmodule(span_R(range b))) = span_R(range b).
LaTeX
$$$$ B.flip.dualSubmodule( B.dualSubmodule(\mathrm{span}_R(\mathrm{range}\, b)) ) = \mathrm{span}_R(\mathrm{range}\, b). $$$$
Lean4
/-- Apply a linear map on the left and right argument of a bilinear form. -/
def comp (B : BilinForm R M') (l r : M →ₗ[R] M') : BilinForm R M :=
B.compl₁₂ l r