I don't think you can derive commutativity from only closure, associativity, identity and inverses.
For example consider the general linear group consisting of nxn matrices with nonzero determinant.
- It is closed (multiplying two matrices with nonzero determinant results in a matrix with nonzero determinant)
- It is associative (matrix multiplication is associative)
- It has an identity
- It has inverses
And yet any two matrices in the general linear group need not commute.
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mGGTitan [NA ] (HotS)
Previously known as mGGTitan
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