y numeric values, the floating-point types
     have several special values:
<P
CLASS="LITERALLAYOUT"
><TT
CLASS="LITERAL"
>Infinity</TT
><br>
<TT
CLASS="LITERAL"
>-Infinity</TT
><br>
<TT
CLASS="LITERAL"
>NaN</TT
></P
>
     These represent the IEEE 754 special values
     <SPAN
CLASS="QUOTE"
>"infinity"</SPAN
>, <SPAN
CLASS="QUOTE"
>"negative infinity"</SPAN
>, and
     <SPAN
CLASS="QUOTE"
>"not-a-number"</SPAN
>, respectively.  (On a machine whose
     floating-point arithmetic does not follow IEEE 754, t