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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def ExcludedVolumeChain(q, Rg, nu):
 """Scattering intensity of a generalized excluded-volume Gaussian chain Inputs: ------- ``q``: independent variable ``Rg``: radius of gyration ``nu``: excluded volume exponent Formula: -------- ``(u^(1/nu)*gamma(0.5/nu)*gammainc_lower(0.5/nu,u)- gamma(1/nu)*gammainc_lower(1/nu,u)) / (nu*u^(1/nu))`` where ``u = q^2*Rg^2*(2*nu+1)*(2*nu+2)/6`` is the reduced scattering variable, ``gamma(x)`` is the gamma function and ``gammainc_lower(x,t)`` is the lower incomplete gamma function. Literature: SASFit manual 6. nov. 2010. Equation (3.60b) """

    u = (q * Rg) ** 2 * (2 * nu + 1) * (2 * nu + 2) / 6.
    return (u ** (0.5 / nu) * gamma(0.5 / nu) * gammainc(0.5 / nu, u) -
            gamma(1. / nu) * gammainc(1. / nu, u)) / (nu * u ** (1. / nu))