added Lexicon.encode_position, Lexicon.decode_position;
added Lexicon.encode_position, Lexicon.decode_position;

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