anchor.diff:  
   types();;                                                                           // the_type_constants database doesn't change
   constants();;                                                                       // the_term_constants database doesn't change
  +infixes();;                                                                         // no change
   axioms();;                                                                          // the_axioms database doesn't change
   definitions();;                                                                     // new boolean definitions
   //  [|- (?!) = (\P. (?) P /\ (!x y. P x /\ P y ==> x = y));
  
positive.code: //   ("F", `:bool`); ("\\/", `:bool->bool->bool`); ("?", `:(A->bool)->bool`);
  //   ("!", `:(A->bool)->bool`); ("==>", `:bool->bool->bool`);
  //   ("/\\", `:bool->bool->bool`); ("T", `:bool`); ("=", `:A->A->bool`)]
  
  
  axioms();;                                                                          // the_axioms database doesn't change
  
negative.code: //   ("F", bool); ("\/", bool->bool->bool); ("?", (A->bool)->bool);
  //   ("!", (A->bool)->bool); ("==>", bool->bool->bool); ("/\", bool->bool->bool);
  //   ("T", bool); ("=", A->A->bool)]
  infixes();;                                                                         // no change
  axioms();;                                                                          // the_axioms database doesn't change
  definitions();;                                                                     // new _FALSITY_ definition
  //  [|- _FALSITY_ <=> F; |- (?!) = (\P. (?) P /\ (!x y. P x /\ P y ==> x = y));
  