- dirac_trace() handles arbitrary expressions (even unexpanded), including

[ginac.git] / ginac / tensor.h

diff --git a/ginac/tensor.h b/ginac/tensor.h
index 7396aca177ee38b36905b94038eed109bae18b67..b077ee4d0c927d8e459250bb0092773b8c876163 100644 (file)
--- a/ginac/tensor.h
+++ b/ginac/tensor.h
@@ -183,6 +183,18 @@ ex epsilon_tensor(const ex & i1, const ex & i2, const ex & i3);
  *  @return newly constructed epsilon tensor */
 ex lorentz_eps(const ex & i1, const ex & i2, const ex & i3, const ex & i4, bool pos_sig = false);
 
+/** Create an epsilon tensor in a 4-dimensional projection of a D-dimensional
+ *  Minkowski space. It vanishes whenever one of the indices is not in the
+ *  set {0, 1, 2, 3}.
+ *
+ *  @param i1 First index
+ *  @param i2 Second index
+ *  @param i3 Third index
+ *  @param i4 Fourth index
+ *  @param pos_sig Whether the signature of the metric is positive
+ *  @return newly constructed epsilon tensor */
+ex eps0123(const ex & i1, const ex & i2, const ex & i3, const ex & i4, bool pos_sig = false);
+
 } // namespace GiNaC
 
 #endif // ndef __GINAC_TENSOR_H__