+ return (lgamma(arg+m+_ex1)-recur).series(rel, order, options);
+}
+
+
+static ex lgamma_conjugate(const ex & x)
+{
+ // conjugate(lgamma(x))==lgamma(conjugate(x)) unless on the branch cut
+ // which runs along the negative real axis.
+ if (x.info(info_flags::positive)) {
+ return lgamma(x);
+ }
+ if (is_exactly_a<numeric>(x) &&
+ !x.imag_part().is_zero()) {
+ return lgamma(x.conjugate());
+ }
+ return conjugate_function(lgamma(x)).hold();