prime.logic

来自「国外的一套开源CRM」· LOGIC 代码 · 共 12 行

// prime.txt contains factor and prime proofs
factor(N, I, J) :- 
    for(I, 2, N), for(J, 2, N), =(N, I*J);

for(I, I, Upper) :- <= (I, Upper);
for(I, Lower, Upper) :- 
    <(Lower, Upper), 
    #(LowerPlusOne, Lower + 1), 
    for(I, LowerPlusOne, Upper);

prime(N) :- not factor(N, _, _);