From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Fri, 30 Mar 2001 17:34:35 +0000 (+0000)
Subject: - dummy index recognition in products was flawed: A.i.i*B.j.j would be
X-Git-Tag: release_0-8-1~38
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=7064a931c4b5bea8c4a924fc9e9edabe5584b57a

- dummy index recognition in products was flawed: A.i.i*B.j.j would be
  treated as a scalar product of A and B, A.j.j.i.i*B.k.l would be 0
  if A was symmetric and B antisymmetric etc.
- removed redundant code for handling d.akl*f.akl contraction; this is
  handled by simplify_indexed() itself since it is a contraction of a
  symmetric with an antisymmetric tensor
---

diff --git a/ginac/color.cpp b/ginac/color.cpp
index 65dcf4ae..675d3274 100644
--- a/ginac/color.cpp
+++ b/ginac/color.cpp
@@ -301,39 +301,27 @@ bool su3d::contract_with(exvector::iterator self, exvector::iterator other, exve
 	GINAC_ASSERT(self->nops() == 4);
 	GINAC_ASSERT(is_ex_of_type(self->op(0), su3d));
 
-	if (is_ex_exactly_of_type(other->op(0), su3d) || is_ex_exactly_of_type(other->op(0), su3f)) {
+	if (is_ex_exactly_of_type(other->op(0), su3d)) {
 
 		// Find the dummy indices of the contraction
 		exvector dummy_indices;
 		dummy_indices = ex_to_indexed(*self).get_dummy_indices(ex_to_indexed(*other));
 
-		if (is_ex_exactly_of_type(other->op(0), su3d)) {
-
-			// d.abc*d.abc=40/3
-			if (dummy_indices.size() == 3) {
-				*self = numeric(40, 3);
-				*other = _ex1();
-				return true;
-
-			// d.akl*d.bkl=5/3*delta.ab
-			} else if (dummy_indices.size() == 2) {
-				exvector a = index_set_difference(ex_to_indexed(*self).get_indices(), dummy_indices);
-				exvector b = index_set_difference(ex_to_indexed(*other).get_indices(), dummy_indices);
-				GINAC_ASSERT(a.size() > 0);
-				GINAC_ASSERT(b.size() > 0);
-				*self = numeric(5, 3) * delta_tensor(a[0], b[0]);
-				*other = _ex1();
-				return true;
-			}
-
-		} else {
-
-			// d.akl*f.bkl=0 (includes the case a=b)
-			if (dummy_indices.size() >= 2) {
-				*self = _ex0();
-				*other = _ex0();
-				return true;
-			}
+		// d.abc*d.abc=40/3
+		if (dummy_indices.size() == 3) {
+			*self = numeric(40, 3);
+			*other = _ex1();
+			return true;
+
+		// d.akl*d.bkl=5/3*delta.ab
+		} else if (dummy_indices.size() == 2) {
+			exvector a = index_set_difference(ex_to_indexed(*self).get_indices(), dummy_indices);
+			exvector b = index_set_difference(ex_to_indexed(*other).get_indices(), dummy_indices);
+			GINAC_ASSERT(a.size() > 0);
+			GINAC_ASSERT(b.size() > 0);
+			*self = numeric(5, 3) * delta_tensor(a[0], b[0]);
+			*other = _ex1();
+			return true;
 		}
 	}
 
diff --git a/ginac/indexed.cpp b/ginac/indexed.cpp
index 0ab989e8..255fed53 100644
--- 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)
diff --git a/ginac/tensor.cpp b/ginac/tensor.cpp
index b180ec9e..414225d2 100644
--- a/ginac/tensor.cpp
+++ b/ginac/tensor.cpp
@@ -333,7 +333,7 @@ bool tensmetric::contract_with(exvector::iterator self, exvector::iterator other
 
 	// If contracting with the delta tensor, let the delta do it
 	// (don't raise/lower delta indices)
-	if (is_ex_exactly_of_type(other->op(0), tensdelta))
+	if (is_ex_of_type(other->op(0), tensdelta))
 		return false;
 
 	// Try to contract first index