This is a stupid question, but perhaps somebody else has had the same stupid question before and found an answer.(adsbygoogle = window.adsbygoogle || []).push({});

Why is a <b>semi</b>group so named? If a group were a set and a binary operation satisfying 2 additional properties, then semigroup would be the perfect name, since it satisfies only 1 additional property, but that's not the case.

Is there some logic to the name? Is it because [tex]\frac{3}{2} = 1[/tex] in integer arithmetic ;-)? Wikipedia and other sources are no help, and I'm hoping there is a logic to the name, as mathematical terminology is usually extremely logical.

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# Semigroups: why semi-?

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