Hi, I got a problem about the series function, I used the following test code(see below or the attached file), the s1 output only gives Order(ep^(-1)), while s2 output indicates that there is a 1/ep^2 term, so the s1 is not correct or I used the series in a wrong way? Thanks a lot! #include <ginac/ginac.h> using namespace GiNaC; using namespace std; int main(int argn, char** args) { symbol x1("x1"),x2("x2"),x3("x3"),x4("x4"); symbol ep("ep"); ex expr = -2*pow(x1,-1 + ep)*(exp(3*ep*Euler)*pow(ep,-1)*pow(x2,-3*ep)* pow(1 + x3 + x4 + x3*x4,-3*ep)* pow(1 + x2 + x3 + x2*x3 + x4 + x2*x4 + x3*x4 + x2*x3*x4,-2 + 4*ep)*tgamma(3*ep) - exp(3*ep*Euler)*pow(ep,-1)*pow(x2,-3*ep)*pow(1 + x3 + x4 + x3*x4,-3*ep)* pow(1 + x2 + x3 + x1*x3 + x2*x3 + x4 + x2*x4 + x3*x4 + x1*x3*x4 + x2*x3*x4, -2 + 4*ep)*tgamma(3*ep)); auto s1 = expr.series(ep,-1); cout << s1.normal() << endl; auto s2 = expr.series(ep,0); cout << s2.normal() << endl; return 0; }