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Theorems · Theorem · group theory

Subsemigroup.isMulCommutative_iSup

∀ {ι : Sort u_1} {M : Type u_2} [inst : Mul M] {S : ι → Subsemigroup M} [hS : ∀ (i : ι), IsMulCommutative ↥(S i)],
  Directed (fun x1 x2 => x1 ≤ x2) S → IsMulCommutative ↥(⨆ i, S i)

The supremum of a directed family of commutative subsemigroups is commutative.

Defined in
Mathlib.Algebra.Group.Subsemigroup.Membership
Cited by
2 results in Mathlib
Foundations
Depth 68 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
MulIsMulCommutative

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Cited by2

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