def noFrags(cords, j):
    x1 = cords[j][0]
    y1 = cords[j][1]
    for i in range(j + 1, len(cords) - 1):
        x2 = cords[i][0]
        y2 = cords[i][1]
        if (x1 + y1 == x2 + y2) or \
            (x1 - y1 == x2 - y2):
            return False
        if x1 == x2 or y1 == y2:
            return False
    return True