eq(start(A),1,[a(A,B,C),loop_cont_a(C)],[B=0,A>=1]).
eq(start(A),1,[a(A,B,C)],[B=1,A>=1]).
eq(start(A),1,[a(100,B,C),loop_cont_a(C)],[B=0,A=100]).
eq(start(A),1,[a(100,B,C)],[B=1,A=100]).
eq(a(A,B,C),1,[a(A-1,B,C)],[A>=1]).
eq(a(A,B,A),0,[],[B=1]).