English
If the R- and S-actions on S and A satisfy compatibility in both ways, then s ⊗ a maps to s • a under lidOfCompatibleSMul.
Русский
Если действия R и S на S и A совместимы в обе стороны, то s ⊗ a отображается как s • a под lidOfCompatibleSMul.
LaTeX
$$$\\mathrm{lidOfCompatibleSMul}\\; R\\; S\\; A\\; (s \\otimes_R\\; a) = s \\cdot a$$$
Lean4
/-- If the R- and S-actions on A and B satisfy `CompatibleSMul` both ways,
then `A ⊗[S] B` is canonically isomorphic to `A ⊗[R] B`. -/
def equivOfCompatibleSMul [CompatibleSMul S R A B] : A ⊗[S] B ≃ₐ[S] A ⊗[R] B
where
__ := mapOfCompatibleSMul R S A B
invFun := mapOfCompatibleSMul S R A B
__ := _root_.TensorProduct.equivOfCompatibleSMul R S A B