Tuesday, 5 July 2016

abstract algebra - Is there a name for this algebraic structure in which acdot(b+c)=(acdotb)cdotc?

Today I was toying around with reflecting points over other points, which I expanded to reflecting lists of points over other lists of points. In the process, I found an interesting yet somewhat bizarre algebraic structure to describe what I was doing, and I would like to know if there exists a name for it or if similar structures have been studied previously.




What follows is a description of the "observed properties" of this algebraic structure. I'm not currently certain which properties should be considered axioms and which are derived from others.



Let (R,+,) be a set R with two binary operations. Furthermore, each element of this set belongs to one of two possible "types." Each element of the first type (to be indicated with a subscript 0 such as a0) represents a "translation," while each element of the second type (a1) represents a "reflection." If a subscript is not provided then the relation should hold regardless of the type.



Addition acts as a "list-like" operator, based on how it interacts with multiplication (described later). It is associative but not commutative.



(a+b)+c=a+(b+c)



When two elements are added, their types xor together.




ax+by=cxy



Any element added to its negation (additive inverse) results in the identity.



a+a=I0
a+I0=I0+a=a



Any type-1 element is its own negation, as is the identity, but all other type-0 elements do not equal their negation.



a1=a1

I0=I0



Swapping the order of operands require that you negate both operands and the expression. The negation does not "distribute" over addition.



a+b=(b+a)



I believe, but am not entirely certain, that (R,+) qualifies as a group.



The multiplication operation represents the translation/reflection of one element by/over another:





  1. reflection of a1 over b1



a1b1=c1



a1a1=a1




  1. translation of a1 by b0




a1b0=c1




  1. reflection of a0 over b1



a0b1=a0





  1. translation of a0 by b0



a0b0=a0



The identity plays a special role here as well:



aI0=a
I0a=I0




Multiplication is a non-associative, non-commutative, yet flexible operation, meaning that the following always holds:



(ab)a=a(ba)



Furthermore,



(ab)a=(ab)a=a(ba)=a(ba)



My somewhat bizarre addition operation was constructed to give multiplication of property of "folding over" addition from the left. That is,




a(b+c)=(ab)c
a(b+c+d++y+z)=abcdyz



I call this "folding" based on programming terminology, and I think this property is one of the more interesting ones. It follows from the above that there is no concept of left(?) division:



a(b+a)=(ab)a=a(ba)
(b+a)(ba)
a0b0=a0=a0c0
b0c0




Multiplication also distributes right, similar to the concept of "mapping" in programming.



(b+c)a=(ba)+(ca)



Negating the first argument of a multiplication expression is equivalent to negating the whole expression.



ab=(ab)



There also also some other useful equations to relate addition, multiplication, and negation:




a+b+a=ba
ab=ccb=a
a0b=a0b






Again, I am not entirely confident on the self-consistency of these relationships. I don't have a real axiomatization yet. With the properties above I've been able to "prove" some simple equivalences such as



cx(cxa1)bx=cx(bxa1cx)




which corresponds to this diagram (which uses "r" for "reflection" instead of ""):



enter image description here






Have similar algebraic structures been named/studied before? I am particularly interested in structures that obey a(b+c)=(ab)c. If possible, I would also like to find ways to reduce the role of "typing" in the properties listed above.

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