%1
diff([],[]).
diff([_],[]).

even(X) :-Y is mod(X,2), Y =:= 0.
diff([A,B|Tail],[Diff|DiffTail]) :- even(B), even(A), Diff is B-A, diff(Tail,DiffTail).
diff([_,_|Tail],DiffTail):- diff(Tail,DiffTail).



%3
diff([],[], []).
diff(_,[], []).
diff([],_, []).

diff([A|TailA], [B|TailB], [Сomposition|СompositionTail]):-
    Сomposition is A-B, diff(TailA, TailB, СompositionTail).

len([], 0).
len([_|T], L) :- len(T, Y), L is Y + 1.

diff_len([], [], 0).
diff_len(A, B, X) :- diff(A, B, Diff), len(Diff, X).


%4
diff([],[], []).
diff(_,[], []).
diff([],_, []).

diff([A|TailA], [B|TailB], [Сomposition|СompositionTail]):-
    Сomposition is A-B, diff(TailA, TailB, СompositionTail).

min([], R, R).
min([X|Xs], WK, R):- X < WK, min(Xs, X, R).
min([X|Xs], WK, R):- X >= WK, min(Xs, WK, R).
min([X|Xs], R):- min(Xs, X, R).

diff_min([], [], []).
diff_min(A, B, X) :- diff(A, B, Diff), min(Diff, X).


%5
composition([],[], []).
composition([_],[], []).
composition([],[_], []).

composition([A|TailA], [B|TailB], [Сomposition|СompositionTail]):-
    Сomposition is A*B, composition(TailA, TailB, СompositionTail).


%6
composition([],[], []).
composition([_],[], []).
composition([],[_], []).

composition([A|TailA], [B|TailB], [Сomposition|СompositionTail]):-
    Сomposition is A*B, composition(TailA, TailB, СompositionTail).

max([], R, R).
max([X|Xs], WK, R):- X > WK, max(Xs, X, R).
max([X|Xs], WK, R):- X =< WK, max(Xs, WK, R).
max([X|Xs], R):- max(Xs, X, R).

del([],_,[]).
del([X|T],X,T):- !.
del([Y|T],X,[Y|R]):- X=\=Y, del(T,X,R).

vsort([],[]).
vsort(X,[A|T]) :- max(X,A), del(X,A,XX), vsort(XX,T).

sort_composition(A, B, X) :- composition(A, B, C), vsort(C, X).


%7
diff([],[], []).
diff(_,[], []).
diff([],_, []).

diff([A|TailA], [B|TailB], [Сomposition|СompositionTail]):-
    Сomposition is A-B, diff(TailA, TailB, СompositionTail).

min([], R, R).
min([X|Xs], WK, R):- X < WK, min(Xs, X, R).
min([X|Xs], WK, R):- X >= WK, min(Xs, WK, R).
min([X|Xs], R):- min(Xs, X, R).

del([],_,[]).
del([X|T],X,T):- !.
del([Y|T],X,[Y|R]):- X=\=Y, del(T,X,R).

vsort([],[]).
vsort(X,[A|T]) :- min(X,A), del(X,A,XX), vsort(XX,T).

sort_diff(A, B, X) :- diff(A, B, C), vsort(C, X).