Hello everyone, I'm trying to define a completely antisymmetric tensor with six indices, the Levi-Civita tensor in six dimensions, but without success. I followed the instructions of the manual but did not work. I tried the following: int main() { varidx xi_1(symbol("\\xi_1"),6), xi_2(symbol("\\xi_2"),6), xi_3(symbol("\\xi_3"),6), xi_4(symbol("\\xi_4"),6), xi_5(symbol("\\xi_5"),6), xi_6(symbol("\\xi_6"),6); symbol epsilon("varepsilon"); ex gamma_7 = indexed(epsilon, sy_anti(0,1,2,3).add(4).add(5), xi_1, xi_2, xi_3, xi_4, xi_5, xi_6) *dirac_gamma(xi_1.toggle_variance())*dirac_gamma(xi_2.toggle_variance()) *dirac_gamma(xi_3.toggle_variance())*dirac_gamma(xi_4.toggle_variance()) *dirac_gamma(xi_5.toggle_variance())*dirac_gamma(xi_6.toggle_variance()); return 0; } Anyone have any tips? Best regards, Gilson.