anchor.diff:  //   ("F", `:bool`); ("\\/", `:bool->bool->bool`); ("?", `:(A->bool)->bool`);
   //   ("!", `:(A->bool)->bool`); ("==>", `:bool->bool->bool`);
   //   ("/\\", `:bool->bool->bool`); ("T", `:bool`); ("=", `:A->A->bool`)]
  +
  +infixes();;
  +//val it : (string * (int * string)) list =
  +//  [("<=>", (2, "right")); ("==>", (4, "right")); ("\/", (6, "right"));
  +//   ("/\", (8, "right")); ("=", (12, "right")); (",", (14, "right"));
  +//   ("o", (26, "right"))]
   
   
   axioms();;                                                                          // the_axioms database doesn't change
  
positive.code: //   |- (?) = (\P. !q. (!x. P x ==> q) ==> q); |- (!) = (\P. P = (\x. T));
  //   |- (==>) = (\p q. p /\ q <=> p);
  //   |- (/\) = (\p q. (\f. f p q) = (\f. f T T)); |- T <=> (\p. p) = (\p. p)]
  !the_implicit_types;;                                                               // no change
  type_abbrevs();;                                                                    // no 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));
  