English
If a is inseparable from b and c inseparable from d, then a·c is inseparable from b·d.
Русский
Если ainseparable a и b, и c inseparable от d, то a·c inseparable от b·d.
LaTeX
$$$\text{Inseparable}(a,c) \land \text{Inseparable}(b,d) \Rightarrow \text{Inseparable}(a c, b d)$$$
Lean4
@[to_additive]
protected theorem mul {a b c d : M} (hab : Inseparable a b) (hcd : Inseparable c d) : Inseparable (a * c) (b * d) :=
hab.smul hcd