const ex& x = *syms.begin();
// make polynomial primitive
ex unit, cont, pp;
poly.unitcontprim(x, unit, cont, pp);
if ( !is_a<numeric>(cont) ) {
const ex& x = *syms.begin();
// make polynomial primitive
ex unit, cont, pp;
poly.unitcontprim(x, unit, cont, pp);
if ( !is_a<numeric>(cont) ) {