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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 _g(self, h, xp, s):
 """Density function for blow and hop moves"""


        nphi = sum(self.phi)

        return (nphi / 2.0) * log(2 * pi) + nphi * \
            log(s) + 0.5 * sum((h - xp) ** 2) / (s ** 2)