def isPosInf(value):
 return ((_sign(value) == 0) and (_exponent(value) == 2047) and _zero_mantissa(value))

def isPosInf ( value ) : return ( ( _sign ( value ) == 0 ) and ( _exponent ( value ) == 2047 ) and _zero_mantissa ( value ) )
determine if the argument is a ieee 754 positive infinity value .