X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Ftensor.h;h=b077ee4d0c927d8e459250bb0092773b8c876163;hp=65c86c45bd5c703407980f390683f2a017f57a92;hb=43e0a8f5ca5e1c48cef5daaf014acdbca4e44568;hpb=fd097c33e414f72c77376ae7ad4fbd630b3ccce6

diff --git a/ginac/tensor.h b/ginac/tensor.h
index 65c86c45..b077ee4d 100644
--- a/ginac/tensor.h
+++ b/ginac/tensor.h
@@ -53,7 +53,7 @@ class tensdelta : public tensor
 
 	// functions overriding virtual functions from bases classes
 public:
-	void print(std::ostream & os, unsigned upper_precedence=0) const;
+	void print(const print_context & c, unsigned level = 0) const;
 	ex eval_indexed(const basic & i) const;
 	bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const;
 };
@@ -68,7 +68,7 @@ class tensmetric : public tensor
 
 	// functions overriding virtual functions from bases classes
 public:
-	void print(std::ostream & os, unsigned upper_precedence=0) const;
+	void print(const print_context & c, unsigned level = 0) const;
 	ex eval_indexed(const basic & i) const;
 	bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const;
 };
@@ -88,7 +88,7 @@ public:
 
 	// functions overriding virtual functions from bases classes
 public:
-	void print(std::ostream & os, unsigned upper_precedence=0) const;
+	void print(const print_context & c, unsigned level = 0) const;
 	ex eval_indexed(const basic & i) const;
 
 	// member variables
@@ -110,7 +110,7 @@ public:
 
 	// functions overriding virtual functions from bases classes
 public:
-	void print(std::ostream & os, unsigned upper_precedence=0) const;
+	void print(const print_context & c, unsigned level = 0) const;
 	ex eval_indexed(const basic & i) const;
 
 	// member variables
@@ -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__