tensor class -contraction

tensor.h

@@ -179,10 +179,10 @@ public:
 
 	Tensor permute_index_groups(const NRPerm<int> &p) const; //rearrange the tensor storage permuting index groups as a whole
 	Tensor unwind_index(int group, int index) const; //separate an index from a group and expand it to full range as the least significant one
+	Tensor contraction(int group, int index, const Tensor &rhs, int rhsgroup, int rhsindex, T alpha=1) const;
 
 	//@@@ general antisymmetrization operator Kucharski style - or that will be left to a code generator?
 	//@@@symmetrize a group, antisymmetrize a group, expand a (anti)symmetric group - obecne symmetry change krome +1 na -1 vse mozne
-	//@@@contraction
 };