how to prevent decomposition



> I'm stuck about one "simple" problem
> I have to keep the "b^2-1" from decomposition to 
> "(b-1)*(b+1)" and don't  know how to reach this. Is there a 
> way to keep the form like 
> "b^2-1"  or (b+1)^2  from expansion?

I don't understand the question.  Maxima will only factor (b^2-1) into
(b-1)*(b+1) if you explicitly call 'factor'.  Could you give some more
context for the question, and perhaps an example?