Corollary 2
Tag 0571, permanent. Cite it as [Bourbaki, Tag 0571].
Algebra, chapter I, § 2. Identity element; cancellable elements; invertible elements
In a monoid the set of invertible elements is stable.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.
Cited by
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Cites
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