Synopsis:

• The Cartesian permutation tensor. To be used with &t and nab(.)[i] to form general Cartesian tensor expressions.

Examples:

> epsilon[1,1,1];
                                       0
> epsilon[1,2,3];
                                       1
> epsilon[1,3,2];
                                       -1
> epsilon[1,j,k] &t a[j] &t b[k];
                             a[2] b[3] - a[3] b[2]
> for i from 1 to 3 do  epsilon[i,j,k] &t a[j] &t b[k]  od; i:='i':
                             a[2] b[3] - a[3] b[2]
                            - a[1] b[3] + a[3] b[1]
                             a[1] b[2] - a[2] b[1]