preserve_behaviour_test.pl

elem_tree_to_list_tree(empty, empty) :- !.

elem_tree_to_list_tree(node(A,X,B), node(NA,[X], NB)) :-
    elem_tree_to_list_tree(A,NA),
    elem_tree_to_list_tree(B,NB).

fib(N,_) :-
    N < 0, !, fail.

fib(0, 0) :- !.

fib(1, 1) :- !.

fib(N, X) :-
    M is N-1,
    K is N-2,
    fib(M,A),
    fib(K,B),
    X is A+B.

golden_ratio(X,R) :-
    next_fib(X,Y),
    R is Y/X.

is_fib(X) :-
    integer(X),
    is_fib(0,X).

is_fib(N,X) :-
    fib(N,P),
    (P == X ->
    true
    ;
    (P < X ->
    M is N+1,
    is_fib(M,X)
    ;
    fail
)
).

my_member(E,[E|_]).

my_member(E,[_|T]) :-
    my_member(E,T).

my_member_bla(E,[E|_]) :- !.

my_member_bla(E,[_|T]) :-
    my_member(E,T).

next_fib(X, Y) :-
    P is 2*X,
    between(X,P,Y),
    Y > X,
    is_fib(Y), !.

next_fib_no_annotations(X,Y) :-
    P is 2*X,
    between(X,P,Y),
    Y > X,
    is_fib(Y), !.

test(normal_next_fib) :-
    next_fib_no_annotations(8,X),
    X =:= 13.

test(spec_next_fib,[true(X=:=13)]) :-
    next_fib(8,X),
    X =:= 13.

test(my_member_create_list, []) :-
    my_member(1,T),
    T = [2,2,2,1,2], !.

test(golden_ratio_one_solution, []) :-
    golden_ratio(1,R),
    R =:= 2,
    findall(X, golden_ratio(34,X), L),
    length(L,1).