Problem Statement

The IEEE floating point specification defines certain 'extreme' floating point values such as minus zero, -0.0, a value distinct from plus zero; not a number, NaN; and plus and minus infinity. The task is to use expressions involving other 'normal' floating point values in your language to calculate these, (and maybe other), extreme floating point values in your language and assign them to variables. Print the values of these variables if possible; and show some arithmetic with these values and variables. If your language can directly enter these extreme floating point values then show it.

Let's start with the solution:

   Inf=: _
   NegInf=: __
   NB. Negative zero cannot be represented in J to be distinct from 0.
   NaN=. _.


   (1 % 0) , (_1 % 0)
_ __
   (1e234 * 1e234) , (_1e234 * 1e234)
_ __
   _ + __         NB. generates NaN error, rather than NaN
|NaN error
|   _    +__

   _ - _          NB. generates NaN error, rather than NaN
|NaN error
|   _    -_
   %_
0
  %__             NB. Under the covers, the reciprocal of NegInf produces NegZero, but this fact isn't exposed to the user, who just sees zero
0


   _ + _
_
   __ + __
__
   Inf + 0
_
   NegInf * 0
0