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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 verifies( self, hash, signature ):
 """Verify that signature is a valid signature of hash. Return True if the signature is valid. """


    # From X9.62 J.3.1.

    G = self.generator
    n = G.order()
    r = signature.r
    s = signature.s
    if r < 1 or r > n-1: return False
    if s < 1 or s > n-1: return False
    c = numbertheory.inverse_mod( s, n )
    u1 = ( hash * c ) % n
    u2 = ( r * c ) % n
    xy = u1 * G + u2 * self.point
    v = xy.x() % n
    return v == r