synced to 1.0

[ginac.git] / ginac / tensor.cpp

diff --git a/ginac/tensor.cpp b/ginac/tensor.cpp
index f04a75c9c668b05249e004bf07dfe69f4c91ccbf..f786c4a193963524ca84483880fe42670b1a515e 100644 (file)
--- a/ginac/tensor.cpp
+++ b/ginac/tensor.cpp
@@ -179,6 +179,13 @@ ex tensdelta::eval_indexed(const basic & i) const
        const idx & i1 = ex_to<idx>(i.op(1));
        const idx & i2 = ex_to<idx>(i.op(2));
 
+       // The dimension of the indices must be equal, otherwise we use the minimal
+       // dimension
+       if (!i1.get_dim().is_equal(i2.get_dim())) {
+               ex min_dim = i1.minimal_dim(i2);
+               return i.subs(lst(i1 == i1.replace_dim(min_dim), i2 == i2.replace_dim(min_dim)));
+       }
+
        // Trace of delta tensor is the (effective) dimension of the space
        if (is_dummy_pair(i1, i2)) {
                try {