def kinem_allowed(q2, par, B, V, lep):
    """True if q2 is in the kinematically allowed region"""
    ml = par['m_'+lep]
    mB = par['m_'+B]
    mV = par['m_'+V]
    if q2 < ml**2 or q2 > (mB-mV)**2:
        return False
    else:
        return True