Maxima Function
collectterms (arg_1, ..., arg_n)
If several expressions have been
simplified with facsum, factorfacsum, factenexpand, facexpten or
factorfacexpten, and they are to be added together, it may be
desirable to combine them using the function collecterms.
collecterms can take as arguments all of the arguments that can be
given to these other associated functions with the exception of
nextlayerfactor, which has no effect on collectterms. The advantage
of collectterms is that it returns a form similar to facsum, but
since it is adding forms that have already been processed by facsum,
it does not need to repeat that effort. This capability is
especially useful when the expressions to be summed are very large.