From: abpetrov <abpetrov@uf...>  20130806 08:32:50

Hi, I tried to define rules for working with fermi operators. Here is the corresponding program: load_package noncom2; operator a,ac; noncom a,a; noncom ac,ac; noncom a,ac; for all i let a(i)*ac(i) = 1  ac(i)*a(i); for all i,j such that i neq j let a(i)*ac(j) = ac(j)*a(i); for all i,j let a(i)*a(j) = a(j)*a(i); for all i,j let aс(i)*aс(j) = aс(j)*aс(i); operator anticom; for all x,y let anticom(x,y) = x*y + y*x; But when I make attempt calculate an anticommutator like anticom( ac(i)*a(j), a(k)); I got error message Segmentation fault What is wrong in my rules? Best regards, Petrov Alexander. 