prologcheatshit

present(Key,tree(Key,_,_)).
present(Key,tree(_,LeftSubTree,_)) :-
present(Key,LeftSubTree).
present(Key,tree(_,_,RightSubTree)) :-
present(Key,RightSubTree).


inserting(Key,null,tree(Key,null,null)).
inserting(Key,tree(Root,LeftSubTree,RightSubTree),tree(Root,NewLeftSubTree,RightSubTree)) :-
    Key<Root,
    inserting(Key,LeftSubTree,NewLeftSubTree).
inserting(Key,tree(Root,LeftSubTree,RightSubTree),tree(Root,LeftSubTree,NewRightSubTree)) :-
    Key>Root,
    inserting(Key,RightSubTree,NewRightSubTree).

add(null,0).
add(tree(X,T1,T2),S):-
    add(T1,S1),
    add(T2,S2),
    S is X+S1+S2.

count_leaves(null,0).
count_leaves(tree(_,null,null),1).
count_leaves(tree(_, L, R), N):-
    count_leaves(L, NL),
    count_leaves(R, NR),
    N is NL + NR.

compute(tree(S,null,null),Result):-
    Result is S.
compute(tree(+,T1,T2),Result):-
    Result is T1 + T2.
compute(tree(-,T1,T2),Result):-
    Result is T1 - T2.
compute(tree(*,T1,T2),Result):-
    Result is T1*T2.
compute(tree(/,T1,T2),Result):-
    Result is T1 / T2.

present(Item,[Item|_]).
present(Item,[_|Tail]) :-
    present(Item,Tail).

concatenating([],List,List).
concatenating([Head|Tail],List,[Head|ResultedTail]) :-
    concatenating(Tail,List,ResultedTail).

predecessors(Item,EntireList,ListOfPredecessors):-
    append(ListOfPredecessors,[Item|_],EntireList).

successors(Item,EntireList,ListOfSuccessors):-
    append(_,[Item|ListOfSuccessors],EntireList).

inserting(item,list,result):-
    append(L1,L2,list),
    append(L1,[item|L2],result).

deleting(item,list,result):-
    append(L1,[item|L2],list),
    append(L1,L2,result).

deletingall(X, [X], []):-!.
deletingall(X, [X|Xs], Y):-!, deletingall(X, Xs, Y).
deletingall(X, [T|Xs], Y):-!, deletingall(X, Xs, Y2), append([T], Y2, Y).

range(X, X, result):-!.
range(X,Y,result):-
    X1 is X+1,
    append()...

preorder(null,[]).
preorder(tree(Root,L,R),List):-
    preorder(L,L1),
    preorder(R,L2),
    append([Root | L1], L2, List).

inorder: append(L1, [Root | L2], List).
postorder: append(L1, L2, aux)
           append(aux, Root, List).