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