Associative

Definition

An operator is associative if:

• [math](xy)z=x(yz)[/math] where [ilmath]xy[/ilmath] denotes the operator acting on [ilmath]x[/ilmath] and [ilmath]y[/ilmath]

In fact given a function [ilmath]\times:S\times S\rightarrow S[/ilmath] we even call the image of [ilmath](x,y)[/ilmath] under [ilmath]\times[/ilmath] the product (or indeed the sum if we're using additive notation)