#include <bits/stdc++.h>
long long mod = 1000000007;
using namespace std;
long long int fast_exp(long long int base, long long int ex) {
  long long int res = 1;
  while (ex > 0) {
    if (ex % 2 == 1) res = (res * base) % mod;
    base = (base * base) % mod;
    ex /= 2;
  }
  return res % mod;
}
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  long long int re = gcd(b, a % b);
  return re;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int t;
  cin >> t;
  while (t--) {
    long long a, b;
    cin >> a >> b;
    long long o = a + b;
    long long p = a - b;
    int fl = 0;
    if (p > 1) {
      cout << "NO\n";
      continue;
    }
    for (long long i = 2; i * i <= o; i++) {
      if (o % i == 0) {
        cout << "NO\n";
        fl = 1;
        break;
      }
    }
    if (fl) continue;
    cout << "YES\n";
  }
  return 0;
}
