pl-files/hittingSetTree.pl

   1 :- [diagnosis].
   2
   3 isHittingSetTree(Tree) :-
   4         isHittingSetTree2(Tree, []). %function to add variable for uniqueness checking
   5
   6 isHittingSetTree2(leaf, _). %when end of branch has been reached
   7 isHittingSetTree2(node([], []), _). %when a node turns empty
   8 isHittingSetTree2(node([X|Xs], [Y|Ys]), Z) :-
   9         not(member(X,Z)), %check if label has already been used up in the tree
  10         append(Z, [X], Appended), %append label to list of checked labels
  11         isHittingSetTree2(Y, Appended), %go into depth
  12         isHittingSetTree2(node(Xs, Ys), Z). %go into width
  13