I find I quickly lose patience when the online "help" files in either of these packages doesn't seem to be helping no matter how I phrase my query. Can someone please tell me how to accomplish the following: I want to multiply out some polynomials (with symbolic coefficients) to get a big hairy polynomial (so far no problem) . . . and then reduce the result modulo setting certain (small) polynomials equal to 0. (It seems that in Mathematica's Simplify command, the Assumptions parameter is intended to do just this. But apparently I can't figure out the syntax, and the "help" files aren't telling.) (What I tried was Simpify[hairypolynomial, {smallpoly = 0}] but it didn't like the syntax for {smallpoly = 0}.) Thanks in advance for any assistance with this. --Dan P.S. In an alternative attempt to get Mathematica to enforce the simple condition that x^5 = 1, I tried just setting x = Exp[2 Pi i/5]. It certainly understood this, since when I typed x^5 it responded with: 2 i Pi Out[2]= E . But an attempt to Simplify that expression left it unchanged. _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele