7 works(william) <- williamW.
9 works(averall) <- averallW.
14 needs(averall, [jack, william]).
18 works(X) & needs(X, Needs) & forall(member(Burgel, Needs), member(Burgel, Workers)).
21 % works(X) & findall(Y, works(Y), Workers) &
22 % needs(X, Needs) & forall(member(Burgel, Needs), member(Burgel, Workers)).
24 %findall(X, burgels(X), L) & length(L, LX) & LX > 1.