English
If M acts faithfully on α, then M acts faithfully on Option α as well: h ↦ eq_of_smul_eq_smul shows equality of actions implies equality of morphisms.
Русский
Если действие M на α верно различимо, то такое же верно и для Action на Option α: равенство действий на some примыкает к равенству морморфизмов.
LaTeX
$$$[FaithfulSMul M α] \Rightarrow [FaithfulSMul M (Option α)]$$$
Lean4
@[to_additive]
instance [FaithfulSMul M α] : FaithfulSMul M (Option α) :=
⟨fun h => eq_of_smul_eq_smul fun b : α => by injection h (some b)⟩