true.
:-false.
goto_theatre:-ap(theatre).
neg_goto_theatre:-ap(nights1).
neg_goto_theatre:-closed_theatre.
ap(theatre):-ok(theatre),not neg_goto_theatre,not closed_theatre.
ap(night_club):-ok(night_club),not neg_goto_night_club,not closed_night_club.
ap(nights1):-ok(nights1),goto_night_club,not party_night.
ap(nights2):-ok(nights2),goto_theatre,not party_night.
ap(invitation):-ok(invitation),not neg_jim_invites_jane.
ok(X):-name(X),oko(X,theatre),oko(X,night_club),oko(X,nights1),oko(X,nights2),oko(X,invitation).
bl(theatre):-ok(theatre),neg_goto_theatre.
bl(theatre):-ok(theatre),closed_theatre.
bl(night_club):-ok(night_club),neg_goto_night_club.
bl(night_club):-ok(night_club),closed_night_club.
bl(nights1):-ok(nights1),not goto_night_club.
bl(nights1):-ok(nights1),party_night.
bl(nights2):-ok(nights2),not goto_theatre.
bl(nights2):-ok(nights2),party_night.
bl(invitation):-ok(invitation),neg_jim_invites_jane.
goto_night_club:-ap(night_club).
neg_goto_night_club:-ap(nights2).
party_night:-saturday.
prec(theatre,night_club):-jim_invites_jane,not neg_prec(theatre,night_club).
prec(night_club,theatre):-jane_invites_jim,not neg_prec(night_club,theatre).
prec(theatre,invitation):-true.
prec(night_club,invitation):-true.
neg_prec(Y,X):-name(X),name(Y),prec(X,Y).
prec(X,Z):-name(X),name(Z),name(Y),prec(X,Y),prec(Y,Z).
jim_invites_jane:-ap(invitation).
neg_jim_invites_jane:-jane_invites_jim.
jane_invites_jim:-jims_birthday.
neg_jane_invites_jim:-jim_invites_jane.
oko(X,Y):-name(X),name(Y),not prec(X,Y).
oko(X,Y):-name(X),name(Y),prec(X,Y),ap(Y).
oko(X,Y):-name(X),name(Y),prec(X,Y),bl(Y).
false:-goto_theatre,neg_goto_theatre.
false:-closed_theatre,neg_closed_theatre.
false:-goto_night_club,neg_goto_night_club.
false:-closed_night_club,neg_closed_night_club.
false:-party_night,neg_party_night.
false:-name(X),name(Y),prec(X,Y),neg_prec(X,Y).
false:-jim_invites_jane,neg_jim_invites_jane.
false:-jane_invites_jim,neg_jane_invites_jim.
false:-saturday,neg_saturday.
false:-jims_birthday,neg_jims_birthday.
name(invitation).
name(nights2).
name(nights1).
name(night_club).
name(theatre).