p.
q.
e(a).
r1:-p.
r2:-p,q.
r3:-p,~q.
r4:-~p,q.
r5:-~p,~q.
r6:-~p.
r7:-e(a).
r8:-e(b).
r9:-p,q.
r10:-p,e(a).
r11:-e(a),q.
r12:-e(b),q.
r13:-p,e(b).
r14:-e(a),~q.
r15:-~p,e(a).
r16:-e(b),~q.
r17:-~p,e(b).
f(X):-e(X),p.
g(X):-p,e(X).
h(X):-e(X),~w.
f1(X):-e(X),~p.
g1(X):-~p,e(X).
h1(X):-e(X),w.
?-p.

