False positives for the LessThan circuit (caused by overflow)

false_positive.js

// https://github.com/iden3/circomlib/blob/master/circuits/comparators.circom

const p = 23;
const N = 2;
var fp = []; // false positive

for (var x = 0; x < p; x++) {
    fp[x] = [];
    for (var y = 0; y < p; y++) {
        fp[x][y] = ' ';
        const diff = (x + (1 << N) - y + p) % p;
        if (diff < (1 << (N + 1))) {       // can pass Num2Bits
            fp[x][y] = 'B';
            if ((diff & (1 << N)) == 0) {  // the logic of LessThan for "true"
                fp[x][y] = 'L';
                if (x >= y) {           // false positive
                    fp[x][y] = 'F';
                }
            }
        }
    }
}

console.log("\nB: can pass Num2Bits   L: and LessThan == 1   F: but false positive\n");
for (var y = p - 1; y >= 0; y--) {
    var s = "";
    for (var x = 0; x < p; x++) {
        s += fp[x][y];
    }
    console.log(s);
}
console.log();

output.txt

% node false_positive.js

B: can pass Num2Bits   L: and LessThan == 1   F: but false positive

BBB               LLLLB
BB               LLLLBB
B               LLLLBBB
               LLLLBBBB
              LLLLBBBB
             LLLLBBBB
            LLLLBBBB
           LLLLBBBB
          LLLLBBBB
         LLLLBBBB
        LLLLBBBB
       LLLLBBBB
      LLLLBBBB
     LLLLBBBB
    LLLLBBBB
   LLLLBBBB
  LLLLBBBB
 LLLLBBBB
LLLLBBBB
LLLBBBB               F
LLBBBB               FF
LBBBB               FFF
BBBB               FFFF