-ex permute_free_index_to_front(const exvector & iv3, const exvector & iv2,
- bool antisymmetric, int * sig)
-{
- // match (return value,iv2) to iv3 by permuting indices
- // iv3 is always cyclic
-
- GINAC_ASSERT(iv3.size()==3);
- GINAC_ASSERT(iv2.size()==2);
-
- *sig=1;
-
- TEST_PERMUTATION(0,1,2, 1);
- TEST_PERMUTATION(0,2,1, -1);
- TEST_PERMUTATION(1,0,2, -1);
- TEST_PERMUTATION(1,2,0, 1);
- TEST_PERMUTATION(2,0,1, 1);
- TEST_PERMUTATION(2,1,0, -1);
- throw(std::logic_error("permute_free_index_to_front(): no valid permutation found"));
-}
-
-unsigned subs_index_in_exvector(exvector & v, const ex & is, const ex & ir)
-{
- exvector::iterator it;
- unsigned replacements=0;
- unsigned current_replacements;
-
- GINAC_ASSERT(is_ex_of_type(is,idx));
- GINAC_ASSERT(is_ex_of_type(ir,idx));
-
- for (it=v.begin(); it!=v.end(); ++it) {
- current_replacements=count_index(*it,is);
- if (current_replacements>0) {
- (*it)=(*it).subs(is==ir);
+ // Sort index vector. This will cause dummy indices come to lie next
+ // to each other (because the sort order is defined to guarantee this).
+ exvector v(it, itend);
+ shaker_sort(v.begin(), v.end(), ex_is_less(), ex_swap());
+
+ // Find dummy pairs and free indices
+ it = v.begin(); itend = v.end();
+ exvector::const_iterator last = it++;
+ while (it != itend) {
+ if (is_dummy_pair(*it, *last)) {
+ out_dummy.push_back(*last);
+ it++;
+ if (it == itend)
+ return;
+ } else {
+ if (!it->is_equal(*last) && ex_to<idx>(*last).is_symbolic())
+ out_free.push_back(*last);