(p.i*p.i).get_free_indices() returned (.i) instead of ()

[ginac.git] / ginac / indexed.cpp

diff --git a/ginac/indexed.cpp b/ginac/indexed.cpp
index 40a6232c1ecdcb02f5f678acd616b79d21b76138..ad17a497a9dc703e52cd435d6901312071beab42 100644 (file)
--- a/ginac/indexed.cpp
+++ b/ginac/indexed.cpp
@@ -48,7 +48,7 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(indexed, exprseq,
 // default constructor
 //////////
 
-indexed::indexed() : symtree(sy_none())
+indexed::indexed() : symtree(not_symmetric())
 {
        tinfo_key = TINFO_indexed;
 }
@@ -57,31 +57,31 @@ indexed::indexed() : symtree(sy_none())
 // other constructors
 //////////
 
-indexed::indexed(const ex & b) : inherited(b), symtree(sy_none())
+indexed::indexed(const ex & b) : inherited(b), symtree(not_symmetric())
 {
        tinfo_key = TINFO_indexed;
        validate();
 }
 
-indexed::indexed(const ex & b, const ex & i1) : inherited(b, i1), symtree(sy_none())
+indexed::indexed(const ex & b, const ex & i1) : inherited(b, i1), symtree(not_symmetric())
 {
        tinfo_key = TINFO_indexed;
        validate();
 }
 
-indexed::indexed(const ex & b, const ex & i1, const ex & i2) : inherited(b, i1, i2), symtree(sy_none())
+indexed::indexed(const ex & b, const ex & i1, const ex & i2) : inherited(b, i1, i2), symtree(not_symmetric())
 {
        tinfo_key = TINFO_indexed;
        validate();
 }
 
-indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3) : inherited(b, i1, i2, i3), symtree(sy_none())
+indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3) : inherited(b, i1, i2, i3), symtree(not_symmetric())
 {
        tinfo_key = TINFO_indexed;
        validate();
 }
 
-indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3, const ex & i4) : inherited(b, i1, i2, i3, i4), symtree(sy_none())
+indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3, const ex & i4) : inherited(b, i1, i2, i3, i4), symtree(not_symmetric())
 {
        tinfo_key = TINFO_indexed;
        validate();
@@ -105,7 +105,7 @@ indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex &
        validate();
 }
 
-indexed::indexed(const ex & b, const exvector & v) : inherited(b), symtree(sy_none())
+indexed::indexed(const ex & b, const exvector & v) : inherited(b), symtree(not_symmetric())
 {
        seq.insert(seq.end(), v.begin(), v.end());
        tinfo_key = TINFO_indexed;
@@ -152,7 +152,7 @@ indexed::indexed(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
                                symtree = sy_anti();
                                break;
                        default:
-                               symtree = sy_none();
+                               symtree = not_symmetric();
                                break;
                }
                const_cast<symmetry &>(ex_to<symmetry>(symtree)).validate(seq.size() - 1);
@@ -499,10 +499,27 @@ exvector ncmul::get_free_indices() const
        return free_indices;
 }
 
+struct is_summation_idx : public std::unary_function<ex, bool> {
+       bool operator()(const ex & e)
+       {
+               return is_dummy_pair(e, e);
+       }
+};
+
 exvector power::get_free_indices() const
 {
-       // Return free indices of basis
-       return basis.get_free_indices();
+       // Get free indices of basis
+       exvector basis_indices = basis.get_free_indices();
+
+       if (exponent.info(info_flags::even)) {
+               // If the exponent is an even number, then any "free" index that
+               // forms a dummy pair with itself is actually a summation index
+               exvector really_free;
+               std::remove_copy_if(basis_indices.begin(), basis_indices.end(),
+                                   std::back_inserter(really_free), is_summation_idx());
+               return really_free;
+       } else
+               return basis_indices;
 }
 
 /** Rename dummy indices in an expression.