# Addition of Extra Generators

It is often the case that a particular expression in the original generators is important in some homomorphic image of the group in the sense that it will very often form a common subexpression of subsequent expression. For this reason, Magma provides facilities to build related SLP-groups in which particular words acquire generator status themselves.

## `AddRedundantGenerators(G, Q): GrpSLP, [ GrpSLPElt ] -> GrpSLP`

An SLP-group $H$ on $n + q$ generators (where $G$ has $n$ generators and $Q$ has $q$ elements). Furthermore, the identification of $G.i$ with $H.i$ ($i\leq n$) and of $Q[i]$ with $H.(n+i)$ is maintained, allowing coercion between $G$ and $H$ and also simple definition of homomorphisms.