replaced FIRSTGOAL by FINDGOAL (backtracking!); improved flexflex handling; tuned sig;
replaced FIRSTGOAL by FINDGOAL (backtracking!);
improved flexflex handling;
tuned sig;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle