English
A group is commutative if the quotient by the center is cyclic.
Русский
Группа коммутативна, если фактор по центру цикличен.
LaTeX
$$commGroupOfCyclicCenterQuotient (f : G →* G') (hf : ker f ≤ center G) : CommGroup G$$
Lean4
/-- A group is commutative if the quotient by the center is cyclic. -/
@[to_additive /-- A group is commutative if the quotient by the center is cyclic. -/
]
def commGroupOfCyclicCenterQuotient [IsCyclic G'] (f : G →* G') (hf : f.ker ≤ center G) : CommGroup G :=
{ show Group G by infer_instance with mul_comm := commutative_of_cyclic_center_quotient f hf }