/* PROTECT : Setting the flags for the system predicates

						Lawrence
						Updated: 16 January 82
*/


$mem(X,[X|_]).
$mem(X,[_|Rest]) :- $mem(X,Rest).


			% Cut must be transparent due to the way it's currently
			%  implemented (this fixes bug that prevented tracing
			%  past cuts).
			% Note that transparent also seem to imply untracable,
			%  which means you don't see cuts at all.

  :- $sysflgs(!,64).


			% This list are all transparent and untracable.

  :-(( $mem(X,[ call(_),(A,B),(A;B),$call(_) ]),
       $sysflgs(X,96), fail  ;  true )).


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

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


			% The following predicates are better off invisible so
			%  they are made untracable as well.

  :-(( $mem(X,[
          write(_), writeq(_), nl, get0(_), get(_), skip(_), put(_), tab(_),
          display(_), ttynl(_), ttytab(_)
         ]),
             $sysflgs(X,32), fail  ;  true )).


			% And now - ALL current predicates are turned into
			%  system predicates (which cannot be redefined, seen
			%  by listing etc).

  :-(( current_atom(A), $current_functor(A,Arity,256,0),
       functor(Pred,A,Arity), $flags(Pred,Flags,Flags\/128), fail  ;  true )).