English
If α is a commutative semigroup, then Finset α is a commutative semigroup under the pointwise product.
Русский
Если α — коммутативная полугруппа, то Finset α образует коммутативную полугруппу при точечном умножении.
LaTeX
$$$$ \\text{If } \\alpha \\text{ is a commutative semigroup, then Finset }\\alpha \\text{ is a commutative semigroup under pointwise product.} $$$$
Lean4
/-- `Finset α` is a `CommSemigroup` under pointwise operations if `α` is. -/
@[to_additive /-- `Finset α` is an `AddCommSemigroup` under pointwise operations if `α` is. -/
]
protected def commSemigroup : CommSemigroup (Finset α) :=
coe_injective.commSemigroup _ coe_mul