You might think of floating-point numbers coming in five varieties: - normal (exponent not minimum or maximum) - zero (minimum exponent, mantissa == 0) - sub

You might think of floating-point numbers coming in five varieties: - normal (exponent not minimum or maximum) - zero (minimum exponent, mantissa == 0) - subnormal (minimum exponent, mantissa != 0) - infinity (maximum exponent, mantissa == 0) - nan (maxmimum exponent, mantissa != 0) NaN is only the last category, strictly. Finite is everything except infinity and nan. Subnormal and zero are collectively denormal. The distinction between "subnormal" and "denormal" is a bit esoteric.