def FoP_update(L, R, t0, t1, u, v):
    """
    We update 'L' according to the link (t0,t1,u,v) and FoP properties.

    :param L:
    :param t0:
    :param t1:
    :param u:
    :param v:
    :return:
    """
    new_arrival = t0
    if v not in L:
        L[v] = new_arrival
        if v not in R:
            R[v] = new_arrival
    elif t0 > L[v]:
        return False
    return True
