function validityChecker(x1, y1, x2, y2) {
    function isValid(x1, y1, x2, y2) {
        const distance = Math.sqrt(Math.pow(x1 - x2, 2) + Math.pow(y1 - y2, 2));

        if (Number.isInteger(distance)) {
            console.log(`{${x1}, ${y1}} to {${x2}, ${y2}} is valid`);
        } else {
            console.log(`{${x1}, ${y1}} to {${x2}, ${y2}} is invalid`);
        }
    }
    isValid(x1, y1, 0, 0);
    isValid(x2, y2, 0, 0);
    isValid(x1, y1, x2, y2);
}