/* VISIBLE : Make normally hidden system predicates visible again

						Lawrence
						Updated: 16 January 82
*/


			% ALL predicates whose names start with a dollar sign
			%  are made untracable (original state).

invisible :-
     ( current_atom(A), name(A,[36|_]), $current_functor(A,Arity,256,0),
       functor(Pred,A,Arity), $flags(Pred,Flags,Flags\/32), fail  ;  true ).


			% ALL predicates whose names start with a dollar sign
			%  are made tracable again.

visible :-
     ( current_atom(A), name(A,[36|_]), $current_functor(A,Arity,256,0),
       functor(Pred,A,Arity), $flags(Pred,Flags,Flags/\2'10011111), fail  ;  true ).


			% Unlock all the system predicates

unlock :-
     ( current_atom(A), $current_functor(A,Arity,128,128),
       functor(Pred,A,Arity), $flags(Pred,Flags,Flags/\2'01111111),
       asserta(unlocked_system_predicate(Pred)), fail
         ;  true ).


			% Lock the system predicates back up again

lock :-
     ( retract(unlocked_system_predicate(Pred)),
       $flags(Pred,Flags,Flags\/128), fail
         ;  true ).