eq(f3(A),1,[f2(A,B,C),loop_cont_f2(C)],[B=0]).
eq(f3(A),1,[f2(A,B,C)],[B=1]).
eq(f2(A,B,C),1,[f2(-1+A,B,C)],[A>=2]).
eq(f2(A,B,C),1,[f2(-1+A,B,C)],[1>=A]).
eq(f2(A,B,A),0,[],[B=1]).