-ex eps0123(const ex & i1, const ex & i2, const ex & i3, const ex & i4, bool pos_sig)
-{
- if (!is_ex_of_type(i1, varidx) || !is_ex_of_type(i2, varidx) || !is_ex_of_type(i3, varidx) || !is_ex_of_type(i4, varidx))
- throw(std::invalid_argument("indices of epsilon tensor must be of type varidx"));
-
- ex dim = ex_to<idx>(i1).get_dim();
- if (dim.is_equal(4))
- return lorentz_eps(i1, i2, i3, i4, pos_sig);
- else
- return indexed(tensepsilon(true, pos_sig), sy_anti(), i1, i2, i3, i4);
-}
-