On 2013-01-30, Peter Pfannenschmid <peter.pfannenschmid at guido-kuebler-gmbh.de> wrote: > (i*j*k + i*k*l)^2, > > I would like to replace i*k by s, so that the expression becomes > > (s*j + s*l)^2. Maybe subst(i = s/k, <whatever>) ? Hope this helps, Robert Dodier