English
A cancellative monoid acts faithfully on itself by left multiplication.
Русский
Относительно левостороннего умножения верно действие подписанного моноида на сам монойд.
LaTeX
$$$\\text{FaithfulSMul } \\alpha \\alpha:$ the map $a \\mapsto (x \\mapsto a\\cdot x)$ is injective.$$
Lean4
/-- `Monoid.toMulAction` is faithful on cancellative monoids. -/
@[to_additive /-- `AddMonoid.toAddAction` is faithful on additive cancellative monoids. -/
]
instance faithfulSMul [RightCancelMonoid α] : FaithfulSMul α α :=
⟨fun h ↦ mul_right_cancel (h 1)⟩