# Math Help - [SOLVED] Composition of mappings notation

1. ## [SOLVED] Composition of mappings notation

Does the order we write composition of mappings change if we are writing the mappings on the left instead of the right?

For instance, are $(g \circ f)(x)$ and $(x)(f \circ g)$ equivalent in general?

2. Originally Posted by Swlabr

For instance, are $(g \circ f)(x)$ and $(x)(f \circ g)$ equivalent in general?
yes. one reason for choosing this order, for example in ring theory, is to avoid dealing with the opposite ring. so if $f,g$ are maps from a module M to itself, i.e. $f,g \in End(M),$ then assuming $*$

is the multiplication operation in the ring $(End (M))^{opp},$ then we have $f * g=g \circ f.$