- dummy index recognition in products was flawed: A.i.i*B.j.j would be

[ginac.git] / ginac / indexed.cpp

diff --git a/ginac/indexed.cpp b/ginac/indexed.cpp
index 0ab989e801baccc8a94d60a7df7306da1822a78f..255fed5322fa1ed77c319a5ab5a567574a7359c5 100644 (file)
--- a/ginac/indexed.cpp
+++ b/ginac/indexed.cpp
@@ -587,16 +587,24 @@ try_again:
                if (!is_ex_of_type(*it1, indexed))
                        continue;
 
-               // Indexed factor found, look for contraction candidates
+               // Indexed factor found, get free indices and look for contraction
+               // candidates
+               exvector free1, dummy1;
+               find_free_and_dummy(ex_to_indexed(*it1).seq.begin() + 1, ex_to_indexed(*it1).seq.end(), free1, dummy1);
+
                exvector::iterator it2;
                for (it2 = it1 + 1; it2 != itend; it2++) {
 
                        if (!is_ex_of_type(*it2, indexed))
                                continue;
 
+                       // Find free indices of second factor and merge them with free
+                       // indices of first factor
+                       exvector un;
+                       find_free_and_dummy(ex_to_indexed(*it2).seq.begin() + 1, ex_to_indexed(*it2).seq.end(), un, dummy1);
+                       un.insert(un.end(), free1.begin(), free1.end());
+
                        // Check whether the two factors share dummy indices
-                       exvector un(ex_to_indexed(*it1).seq.begin() + 1, ex_to_indexed(*it1).seq.end());
-                       un.insert(un.end(), ex_to_indexed(*it2).seq.begin() + 1, ex_to_indexed(*it2).seq.end());
                        exvector free, dummy;
                        find_free_and_dummy(un, free, dummy);
                        if (dummy.size() == 0)