static RCP<const Basic> diff(const Sec &self, const RCP<const Symbol> &x) { return mul(mul(tan(self.get_arg()), sec(self.get_arg())), self.get_arg()->diff(x)); }
void bvisit(const Sec &x) { apply(result_, *(x.get_arg())); mpfr_sec(result_, result_, rnd_); }