eq(f0(A,B),1,[f1(A,B,C,D,E),loop_cont_f1(D,E)],[C=0,A>=1,0>=B+1]).
eq(f0(A,B),1,[f1(A,B,C,D,E)],[C=1,A>=1,0>=B+1]).
eq(f1(A,B,C,D,E),1,[f1(A-B,B,C,D,E)],[A>=B+1,0>=B+1]).
eq(f1(A,B,C,A,B),0,[],[C=1]).