returns 1 if "a*b + add" has no negative terms/factors and doesn't overflow

after we see SOS

* @brief Returns true iff the storing of predecessors is enabled. * * @retval true iff the storing of predecessors is enabled. * @sa d

Tangent function. \param arg function argument \return tangent value of \a arg template<typename T> typename enable<expr,T>::type tan(T arg) { return

Gamma function. \param arg function argument \return gamma function value of \a arg template<typename T> typename enable<expr,T>::type tgamma(T arg) {