rt，怎么从gcd(lcmj≠i(aj),ai)<aigcd(lcm_{j\neq i}(a_j),a_i)<a_igcd(lcmj=i(aj),ai)<ai转化为lcmj≠i(gcd(ai,aj))<ailcm_{j\neq i}(gcd(a_i,a_j))<a_ilcmj=i(gcd(ai,aj))<ai
