+static unsigned clifford_check3(void)
+{
+ // checks traces
+
+ unsigned result = 0;
+
+ symbol dim("D"), m("m"), q("q");
+ varidx mu(symbol("mu"), dim), nu(symbol("nu"), dim);
+ scalar_products sp;
+ ex e;
+
+ sp.add(q, q, pow(q, 2));
+
+ e = pow(m, 2) * indexed(q, mu) * indexed(q, nu)
+ * dirac_gamma(mu.toggle_variance()) * dirac_gamma(nu.toggle_variance());
+ e = dirac_trace(e).simplify_indexed(sp);
+ result += check_equal(e, 4*pow(m, 2)*pow(q, 2));
+
+ return result;
+}
+