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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 signed_gt(a, b):
 """ Return a single bit result of signed greater than comparison. """

    a, b = match_bitwidth(as_wires(a), as_wires(b), signed=True)
    r = b - a
    return r[-1] ^ (~a[-1]) ^ (~b[-1])