A while ago, about to years maybe, i accidentaly stumbled upon a wikipedia article regarding some wierd mathemataics, which had a ruleset that rendered 3 * 4 not the same as 4 * 3. That day i didn't care, i do now. Anyone know what this is?

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Anonymous Sat May 28 17:43:39 2011 No.3137536 [Reply] [Original]

A while ago, about to years maybe, i accidentaly stumbled upon a wikipedia article regarding some wierd mathemataics, which had a ruleset that rendered 3 * 4 not the same as 4 * 3.
That day i didn't care, i do now.
Anyone know what this is?

>>	Anonymous Sat May 28 17:46:39 2011 No.3137541 http://en.wikipedia.org/wiki/Commutativity you are looking for "non-commutative"

>>	Anonymous Sat May 28 17:46:39 2011 No.3137548 There are so many contexts in which that kind of rule applies. tl;dr you can invent any kind of binary operator you want, and people tend to use * as the symbol for any such operator because it conveniently already exists on our keyboards.

>>	Anonymous Sat May 28 17:47:39 2011 No.3137553 Multiplication on matrices can be defined in a reasonably straightforward way, but it is non-commutative in general. Some specific subsets are commutative, like when you use matrices to model complex numbers.

>>	Anonymous Sat May 28 17:48:39 2011 No.3137555 >>3137541 >>3137548 Related. http://en.wikipedia.org/wiki/Nonabelian_group

>>	Anonymous Sat May 28 17:52:39 2011 No.3137583 kthnx

>>	Anonymous Sat May 28 19:40:39 2011 No.3138154 http://en.wikipedia.org/wiki/Noncommutative_geometry

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