English
Extends the left action to a generic group action by g on v1, describing how toMatrix changes when precomposing by a linear action.
Русский
Расширяет левое действие на общий случай: как меняется toMatrix при предобразовании через линейное действие.
LaTeX
$$$\\forall g, f:\\; \\text{toMatrix } (g \\cdot v_1) v_2 f = \\text{toMatrix } v_1 v_2 (f \\circ (\\text{DistribMulAction.toLinearMap } R M_1 g)).$$$
Lean4
theorem toMatrix_smulBasis_left {G} [Group G] [DistribMulAction G M₁] [SMulCommClass G R M₁] (g : G) (f : M₁ →ₗ[R] M₂) :
LinearMap.toMatrix (g • v₁) v₂ f = LinearMap.toMatrix v₁ v₂ (f ∘ₗ DistribMulAction.toLinearMap _ _ g) := by rfl