test :- a, fail.
test :- a(0), fail.
test :- test_prop, test_datalog.

test_prop :-
	( a -> writeln('a is true') ; writeln('a is false') ),
	( b -> writeln('b is true') ; writeln('b is false') ),
	( c -> writeln('c is true') ; writeln('c is false') ),
	( d -> writeln('d is true') ; writeln('d is false') ),
	( e -> writeln('e is true') ; writeln('e is false') ),
	( f -> writeln('f is true') ; writeln('f is false') ),
	( g -> writeln('g is true') ; writeln('g is false') ).

test_datalog :-
	( a(0) -> writeln('a(0) is true') ; writeln('a(0) is false') ),
	( b(0) -> writeln('b(0) is true') ; writeln('b(0) is false') ),
	( c(0) -> writeln('c(0) is true') ; writeln('c(0) is false') ),
	( d(0) -> writeln('d(0) is true') ; writeln('d(0) is false') ),
	( e(0) -> writeln('e(0) is true') ; writeln('e(0) is false') ),
	( f(0) -> writeln('f(0) is true') ; writeln('f(0) is false') ),
	( g(0) -> writeln('g(0) is true') ; writeln('g(0) is false') ).

%---------------------------------------------
:- table a/0, b/0, c/0, e/0, d/0, g/0, f/0.

a :- b,c.

b :- e.
b :- d.

e :- b,f.

d.

c :- tnot(e).
c :- g.

g.

f :- fail.

%---------------------------------------------
:- table a/1, b/1, c/1, e/1, d/1, g/1, f/1.

a(X) :- b(X), c(X).

b(X) :- e(X).
b(X) :- d(X).

e(X) :- b(X), f(X).

d(X) :- X = 0.

c(X) :- tnot(e(X)).
c(X) :- g(X).

g(X) :- X = 0.

f(_) :- fail.