English
For all s,t ⊆ α, the lower closure distributes over multiplication: lowerClosure(s) · t = lowerClosure(s · t).
Русский
Нижнее замыкание распределяется по умножению: нижнее_замыкание(s) · t = нижнее_замыкание(s · t).
LaTeX
$$$\forall s,t \subseteq \alpha:\; \operatorname{lowerClosure}(s) \cdot t = \operatorname{lowerClosure}(s \cdot t)$$$
Lean4
@[to_additive]
theorem lowerClosure_mul : ↑(lowerClosure s) * t = lowerClosure (s * t) :=
by
simp_rw [mul_comm _ t]
exact mul_lowerClosure _ _