Dear GAP Forum,
I think this will be an easy question to answer. I'm looking for the GAP
equivalent of e.g. Maple's 'subs' procedure, which performs substitutions of
variables, expressions, etc. in expressions. In particular, I'd like to
substitute a variable for an expression in a polynomial. I know I could
write a routine using Position and the list accessing functions, but matters
become complicated when it comes to, for example, exponents of the expression
to be replaced. Is there an easier way ?

Thanks
-Lewis McCarthy (lmccarth@klingon.cs.umass.edu)