def calculate_condensate_params(Rvi, Bgi):
    """
    Calculate theoretically the undefined properties of gas-condensate (Bo, Rs)

    Input:
    Rvi: initial Rv, float
    Bgi: initial Bg, float

    Output:
    Rsi: initial Rs, float
    Boi: initial Bo, float
    """

    Rsi = 1 / Rvi
    Boi = Rsi * Bgi

    return(Rsi, Boi)