#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  long long a, b;
  cin >> t;
  while (t--) {
    cin >> a >> b;
    long long temp = a + b;
    if (a - b == 1) {
      int flag = 0;
      long long i;
      int n = sqrt(temp);
      if (temp <= 1) {
        cout << "NO" << endl;
        continue;
      }
      if (temp <= 3) {
        cout << "YES" << endl;
        continue;
      }
      if (temp % 2 == 0) {
        cout << "NO" << endl;
        continue;
      }
      for (i = 3; i <= n + 1; i += 2) {
        if ((temp % (1ll * i)) == 0) {
          flag = 1;
          break;
        }
      }
      if (flag)
        cout << "NO" << endl;
      else
        cout << "YES" << endl;
    } else
      cout << "NO" << endl;
  }
}
