revert 'defs' advertisement; removed PG/xemacs note, which is actually wrong now; tuned;
revert 'defs' advertisement;
removed PG/xemacs note, which is actually wrong now;
tuned;

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