From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Mon, 30 Jul 2001 20:02:34 +0000 (+0000)
Subject: epsilon tensor contractions evaluate to metric tensors instead of deltas,
X-Git-Tag: release_0-9-2~8
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=d1a4416a1bb37290a42250d871b7b52e35f64e0a

epsilon tensor contractions evaluate to metric tensors instead of deltas,
which is more general
---

diff --git a/ginac/tensor.cpp b/ginac/tensor.cpp
index 0d93e652..7b3d1417 100644
--- a/ginac/tensor.cpp
+++ b/ginac/tensor.cpp
@@ -507,9 +507,14 @@ bool tensepsilon::contract_with(exvector::iterator self, exvector::iterator othe
 		// Contraction of two epsilon tensors is a determinant
 		ex dim = ex_to<idx>(self->op(1)).get_dim();
 		matrix M(num, num);
-		for (int i=0; i<num; i++)
-			for (int j=0; j<num; j++)
-				M(i, j) = delta_tensor(self->op(i+1), other->op(j+1));
+		for (int i=0; i<num; i++) {
+			for (int j=0; j<num; j++) {
+				if (minkowski)
+					M(i, j) = lorentz_g(self->op(i+1), other->op(j+1), pos_sig);
+				else
+					M(i, j) = metric_tensor(self->op(i+1), other->op(j+1));
+			}
+		}
 		int sign = minkowski ? -1 : 1;
 		*self = sign * M.determinant().simplify_indexed();
 		*other = _ex1();