def _Backward2_P_hs(h, s):
    """Backward equation for region 2, P=f(h,s)

    Parameters
    ----------
    h : float
        Specific enthalpy, [kJ/kg]
    s : float
        Specific entropy, [kJ/kgK]

    Returns
    -------
    P : float
        Pressure, [MPa]
    """
    sfbc = 5.85
    hamin = _hab_s(s)
    if h <= hamin:
        P = _Backward2a_P_hs(h, s)
    elif s >= sfbc:
        P = _Backward2b_P_hs(h, s)
    else:
        P = _Backward2c_P_hs(h, s)
    return P
def _Backward2_P_hs ( h , s ) : sfbc = 5.85 hamin = _hab_s ( s ) if h <= hamin : P = _Backward2a_P_hs ( h , s ) elif s >= sfbc : P = _Backward2b_P_hs ( h , s ) else : P = _Backward2c_P_hs ( h , s ) return P
Backward equation for region 2, P=f(h,s)

    Parameters
    ----------
    h : float
        Specific enthalpy, [kJ/kg]
    s : float
        Specific entropy, [kJ/kgK]

    Returns
    -------
    P : float
        Pressure, [MPa]