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Talk:Identity element/Archive 1

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Archive 1

Magma?

Clarification needed. The description says "Let (S,*) be a set S with a binary operation * on it (known as a magma)", but Magma (algebra) is defined as "a set M equipped with a single binary operation", which is circular. Why is a binary operation * known as a magma? Or is the "(known as a magma)" supposed to refer to "(S,*)"? If so perhaps it would be clearer to re-word the description as "Let (S,*), known as a magma, be a set S with a binary operation * on it". -- DBooth (talk) 22:07, 24 February 2010 (UTC)

No. (S,*) is not known as magma, a set with a binary operation is known as magma. (On Wikipedia, that is. The rest of the world calls it "groupoid".) There is nothing circular about it, it's just that the same definition is stated twice (once here and once in the magma article).—Emil J. 11:07, 25 February 2010 (UTC)