English
In a canonically ordered monoid, the meet with a distributes over multiplication: min(a, b c) = min(a, min(a,b) · min(a,c)).
Русский
В канонически упорядоченном моноиде операция meet распределяется над умножением: min(a, b c) = min(a, min(a,b) · min(a,c)).
LaTeX
$$\min(a, bc) = \min\big(a, \min(a,b) \cdot \min(a,c)\big)$$
Lean4
@[to_additive]
theorem min_mul_distrib (a b c : α) : min a (b * c) = min a (min a b * min a c) :=
by
rcases le_total a b with hb | hb
· simp [hb, le_mul_right]
· rcases le_total a c with hc | hc
· simp [hc, le_mul_left]
· simp [hb, hc]