[J3] Question regarding valid set of values

[Steven G. Kargl]

On Thu, May 20, 2021 at 07:32:29PM +0200, Thomas König via J3 wrote:
> 
> Hi,
> 
> I have some trouble finding where the standard clearly
> forbids something.
> 
> Consider the program
> 
>   integer :: i
>   i = huge(i)
>   write (*,*) i + 1
> end
> 

I believe you're looking for

  10.1.5.2.4 Evaluation of numeric intrinsic operations

  1 The execution of any numeric operation whose result is not defined by
    the arithmetic used by the processor is prohibited.

This isn't a numbered constraint, so a Fortran processor is not
required to report a possible problem.

I suppose some might argument that, for example, wrap-around
semantics of twos-complement integer arithmetic means the
result is definable. 

-- 
Steve