+ case info_flags::negative: {
+ bool neg = false;
+ epvector::const_iterator i = seq.begin(), end = seq.end();
+ while (i != end) {
+ const ex& factor = recombine_pair_to_ex(*i++);
+ if (factor.info(info_flags::positive))
+ continue;
+ else if (factor.info(info_flags::negative))
+ neg = !neg;
+ else
+ return false;
+ }
+ if (overall_coeff.info(info_flags::negative))
+ neg = !neg;
+ return neg;
+ }
+ case info_flags::negint: {
+ bool neg = false;
+ epvector::const_iterator i = seq.begin(), end = seq.end();
+ while (i != end) {
+ const ex& factor = recombine_pair_to_ex(*i++);
+ if (factor.info(info_flags::posint))
+ continue;
+ else if (factor.info(info_flags::negint))
+ neg = !neg;
+ else
+ return false;
+ }
+ if (overall_coeff.info(info_flags::negint))
+ neg = !neg;
+ else if (!overall_coeff.info(info_flags::posint))
+ return false;
+ return neg;
+ }