- g~mu_mu contraction returns Dim for general Lorentz indices and Dim-dimP

[ginac.git] / ginac / lortensor.cpp

diff --git a/ginac/lortensor.cpp b/ginac/lortensor.cpp
index f9d5f44a8196be1eadbfce0c064f7cab21c33ccf..e8f4f87312d9070d5e2b826affbeddb40f60bf37 100644 (file)
--- a/ginac/lortensor.cpp
+++ b/ginac/lortensor.cpp
@@ -321,7 +321,10 @@ ex lortensor::eval(int level) const
                                return _ex0();
                        }
                } else if (idx1.is_symbolic() && idx1.is_co_contra_pair(idx2)) {
-                       return Dim();
+                       if (idx1.is_orthogonal_only())
+                               return Dim() - idx1.get_dim_parallel_space();
+                       else
+                               return Dim();
                }
        }
        return this -> hold();