def Lastovka_Shaw_integral(T, similarity_variable, cyclic_aliphatic=False):
a = similarity_variable<EOL>if cyclic_aliphatic:<EOL><INDENT>A1 = -<NUM_LIT><EOL>A2 = <NUM_LIT><EOL>first = A1 + A2*a<EOL><DEDENT>else:<EOL><INDENT>A1 = <NUM_LIT><EOL>A2 = <NUM_LIT><EOL>A3 = <NUM_LIT> <EOL>A4 = <NUM_LIT><EOL>first = A2 + (A1-A2)/(<NUM_LIT:1.>+exp((a-A3)/A4)) <EOL><DEDENT>B11 = <NUM_LIT><EOL>B12 = <NUM_LIT><EOL>C11 = <NUM_LIT><EOL>C12 = <NUM_LIT><EOL>B21 = <NUM_LIT><EOL>B22 = <NUM_LIT><EOL>C21 = <NUM_LIT><EOL>C22 = <NUM_LIT><EOL>return <NUM_LIT>*(T*first - (B11 + B12*a)*(-C11 - C12*a)**<NUM_LIT:2>/(-C11 - C12*a + (C11 <EOL>+ C12*a)*exp((-C11 - C12*a)/T)) - (B21 + B22*a)*(-C21 - C22*a)**<NUM_LIT:2>/(-C21 <EOL>- C22*a + (C21 + C22*a)*exp((-C21 - C22*a)/T)))<EOL>
r'''Calculate the integral of ideal-gas constant-pressure heat capacitiy 
    with the similarity variable concept and method as shown in [1]_.

    Parameters
    ----------
    T : float
        Temperature of gas [K]
    similarity_variable : float
        similarity variable as defined in [1]_, [mol/g]

    Returns
    -------
    H : float
        Difference in enthalpy from 0 K, [J/kg]

    Notes
    -----
    Original model is in terms of J/g/K. Note that the model is for predicting
    mass heat capacity, not molar heat capacity like most other methods!
    Integral was computed with SymPy.

    See Also
    --------
    Lastovka_Shaw
    Lastovka_Shaw_integral_over_T

    Examples
    --------
    >>> Lastovka_Shaw_integral(300.0, 0.1333)
    5283095.816018478

    References
    ----------
    .. [1] Lastovka, Vaclav, and John M. Shaw. "Predictive Correlations for
       Ideal Gas Heat Capacities of Pure Hydrocarbons and Petroleum Fractions."
       Fluid Phase Equilibria 356 (October 25, 2013): 338-370.
       doi:10.1016/j.fluid.2013.07.023.