English
The submonoid generated by a set always contains that set: s ⊆ closure(s).
Русский
Подмономоид, порожденный множестом, всегда содержит это множество: s ⊆ closure(s).
LaTeX
$$$ s \\subseteq \\operatorname{closure}(s) $$$
Lean4
/-- The submonoid generated by a set includes the set. -/
@[to_additive (attr := simp, aesop safe 20 (rule_sets := [SetLike])) /--
The `AddSubmonoid` generated by a set includes the set. -/
]
theorem subset_closure : s ⊆ closure s := fun _ hx => mem_closure.2 fun _ hS => hS hx