if( A, B, C ) :-
	( A *-> 
		B
		;
		C
	).

skip_line :- skip( 10 ).

file_exists( File ) :-
	exists_file( File ).

bb_put( Key, Value ) :-
	% flag( Key, _Old, Value ).
    % fixme: Key must be atom- make sure we want the nb (non-backtrackable version)
    nb_setval( Key, Value ).

bb_get( Key, Value ) :-
	% flag( Key, Value, Value ).
    nb_getval( Key, Value ).

nth( A, B, C ) :- nth1( A, B, C ).