Hi all, I wonder is there a way or method to simplify the expression with a sy_anti tensor contracted with a lorent_g to 0? Please have a look at the following code, I expect ret is 0, and the output looks like “A~b~a.c~c”, it is actually 0 due to the sy_anti, but I wonder, is there a way or a method to simplify those expression directly to 0? Thanks very much! using namespace GiNaC; using namespace std; int main(int argc, char** argv) { symbol a("a"), b("b"), c("c"), d("d"), A("A"); symbol D("D"); varidx ia(a,D), ib(b,D), ic(c,D), id(d,D); auto ret = indexed(A, sy_anti(0,1,2,3), ia,ib,ic,id) * lorentz_g(ic.toggle_variance(), id.toggle_variance()); cout << simplify_indexed(ret) << endl; return 0; } Best regards! Feng