Thank you for your answer.
The example I gave is part of a bigger class of procedures. I am working with several polynomials and part of my task was to convert the polynomial structure into a list, sort those lists by different monomial orderings, and then return the differently sortet polynomials.
The problem occurs, when I want to switch back to the representation of the polynomials as a sum, so that the user (me) can see, that the polynomials has been sorted and is in different order (if this is the case), but still looks like a polynomial.
But each time I do this, Maple chooses to use its old representation of the polynomial stored in its simplification table.
That is why I am looking for ways to override or delete those entries within an acitve Maple Session, or to tell Maple not to look up those values.
If you have any suggestions, please let me know.