- (a+b)*gamma5 was incorrectly rewritten as -gamma5*(a+b)

diff --git a/check/exam_clifford.cpp b/check/exam_clifford.cpp
index 287a600d10882700ac53a1e28098811f45327082..fc97ac02447fb81a89d6c71e500f4720d04a5ff9 100644 (file)
--- a/check/exam_clifford.cpp
+++ b/check/exam_clifford.cpp
@@ -173,6 +173,17 @@ static unsigned clifford_check3(void)
        e = dirac_trace(e).simplify_indexed(sp);
        result += check_equal(e, 4*(2*ldotq*ldotq + q*q*ldotq - q*q*l*l + q*q*m*m).expand());
 
+       // stuff that had problems in the past
+       ex prop = dirac_slash(q, dim) - m * dirac_ONE();
+       e = dirac_slash(l, dim) * dirac_gamma5() * dirac_slash(l, dim) * prop;
+       e = dirac_trace(dirac_slash(q, dim) * e) - dirac_trace(m * e)
+         - dirac_trace(prop * e);
+       result += check_equal(e, 0);
+
+       e = (dirac_gamma5() + dirac_ONE()) * dirac_gamma5();
+       e = dirac_trace(e);
+       result += check_equal(e, 4);
+
        return result;
 }
 

diff --git a/ginac/clifford.cpp b/ginac/clifford.cpp
index f6a511c4a3c8f21002b58daf1adf2b3e269759e7..13bb8b0e7010a30f02d0ee0c777c84ba960017d2 100644 (file)
--- a/ginac/clifford.cpp
+++ b/ginac/clifford.cpp
@@ -281,7 +281,7 @@ ex clifford::simplify_ncmul(const exvector & v) const
        // Remove superfluous ONEs
        exvector::const_iterator cit = v.begin(), citend = v.end();
        while (cit != citend) {
-               if (!is_a<diracone>(cit->op(0)))
+               if (!is_a<clifford>(*cit) || !is_a<diracone>(cit->op(0)))
                        s.push_back(*cit);
                cit++;
        }
@@ -296,7 +296,7 @@ ex clifford::simplify_ncmul(const exvector & v) const
                        exvector::iterator it = next_to_last;
                        while (true) {
                                exvector::iterator it2 = it + 1;
-                               if (!is_a<diracgamma5>(it->op(0)) && is_a<diracgamma5>(it2->op(0))) {
+                               if (is_a<clifford>(*it) && is_a<clifford>(*it2) && !is_a<diracgamma5>(it->op(0)) && is_a<diracgamma5>(it2->op(0))) {
                                        it->swap(*it2);
                                        sign = -sign;
                                        something_changed = true;
@@ -312,7 +312,7 @@ ex clifford::simplify_ncmul(const exvector & v) const
        }
 
        // Remove squares of gamma5
-       while (s.size() >= 2 && is_a<diracgamma5>(s[0].op(0)) && is_a<diracgamma5>(s[1].op(0))) {
+       while (s.size() >= 2 && is_a<clifford>(s[0]) && is_a<clifford>(s[1]) && is_a<diracgamma5>(s[0].op(0)) && is_a<diracgamma5>(s[1].op(0))) {
                s.erase(s.begin(), s.begin() + 2);
                something_changed = true;
        }
@@ -321,10 +321,10 @@ ex clifford::simplify_ncmul(const exvector & v) const
        if (s.size() >= 2) {
                exvector::iterator it, itend = s.end() - 1;
                for (it = s.begin(); it != itend; ++it) {
-                       if (!is_a<clifford>(it[0]))
-                               continue;
                        ex & a = it[0];
                        ex & b = it[1];
+                       if (!is_a<clifford>(a) || !is_a<clifford>(b))
+                               continue;
                        if (is_a<diracgamma>(a.op(0)) && is_a<diracgamma>(b.op(0))) {
                                const ex & ia = a.op(1);
                                const ex & ib = b.op(1);