@Override public Set<Statement> sum(final IGASState<Set<Statement>,Set<Statement>,Set<Statement>> state,final Set<Statement> left,final Set<Statement> right){
  final Set<Statement> tmp=new LinkedHashSet<Statement>(left);
  tmp.addAll(right);
  return tmp;
}

@ Override public Set < Statement > sum ( final IGASState < Set < Statement > , Set < Statement > , Set < Statement > > state , final Set < Statement > left , final Set < Statement > right ) { final Set < Statement > tmp = new LinkedHashSet < Statement > ( left ) ; tmp . addAll ( right ) ; return tmp ; }
set union over the gathered edges .
