English
If a is star-normal, then r • a is star-normal for any r.
Русский
Если a звёздно-нормален, то для любого r элемент r • a звёздно-нормален.
LaTeX
$$$\forall r\in R,\; \forall a\in A,\; IsStarNormal(a) \Rightarrow IsStarNormal(r\cdot a)$$$
Lean4
protected instance smul {R A : Type*} [SMul R A] [Star R] [Star A] [Mul A] [StarModule R A] [SMulCommClass R A A]
[IsScalarTower R A A] (r : R) (a : A) [ha : IsStarNormal a] : IsStarNormal (r • a) where
star_comm_self := star_smul r a ▸ ha.star_comm_self.smul_left (star r) |>.smul_right r