static RCP<const Basic> diff(const ACos &self, const RCP<const Symbol> &x) { return mul(div(minus_one, sqrt(sub(one, pow(self.get_arg(), i2)))), self.get_arg()->diff(x)); }
void bvisit(const ACos &x) { apply(result_, *(x.get_arg())); mpfr_acos(result_, result_, rnd_); }