English
If the element x is central in M, then its image under any MulEquivClass is central in N.
Русский
Если x центральен в M, то образ x через эквивалентность MulEquivClass перестает быть центральным в N.
LaTeX
$$∀ e, x ∈ center M, e x ∈ center N$$
Lean4
@[to_additive]
theorem _root_.MulEquivClass.apply_mem_center {F} [EquivLike F M N] [Mul M] [Mul N] [MulEquivClass F M N] (e : F)
{x : M} (hx : x ∈ Set.center M) : e x ∈ Set.center N :=
by
let e := MulEquivClass.toMulEquiv e
change e x ∈ Set.center N
constructor <;>
(intros; apply e.symm.injective;
simp only [map_mul, e.symm_apply_apply, (hx.comm _).eq, (isMulCentral_iff _).mp hx, ← hx.right_comm])