English
Algebra maps interact with gradedMul in a way that mimics linearity and compatibility with the grading.
Русский
Алгебраобраза взаимодействуют с gradedMul так же, как линейность и совместимость со степенями градации.
LaTeX
$$$$ gradedMul_R( x, algebraMap_R(r) ) = algebraMap_R(r) \otimes x. $$$$
Lean4
theorem algebraMap_gradedMul (r : R) (x : (⨁ i, 𝒜 i) ⊗[R] (⨁ i, ℬ i)) :
gradedMul R 𝒜 ℬ (algebraMap R _ r ⊗ₜ 1) x = r • x :=
by
suffices gradedMul R 𝒜 ℬ (algebraMap R _ r ⊗ₜ 1) = DistribMulAction.toLinearMap R _ r by
exact DFunLike.congr_fun this x
ext ia a ib b
dsimp
erw [tmul_of_gradedMul_of_tmul]
rw [zero_mul, uzpow_zero, one_smul, smul_tmul']
erw [one_mul, _root_.Algebra.smul_def]