Re: About the F-22 software bug

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Fri, 5 Feb 2010 08:50:31 -0800 (PST), Hibou57 (Yannick Duch�ne) wrote:

> On 5 f�v, 11:31, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
> wrote:
>> And shift does not solve the problem anyway, if that existed. The potential
>> problem is that the angle is not a real number. It could be represented by
>> one, but then the operations like +, -, *, /, =, /= must be replaced and
>> ones like <, >, <=, >= disallowed.
> 
> I would have thought for reals, operations like +, -, *, /, <, >, /=
> changed and =, <=, >= disallowed
> Is there something I don't understand ?

You can compare angles, but cannot order them, at least while keeping
transitivity of ">":

   a > b /\ b > c  =>  a > c

Also a combination of operations like yours is impossible:

   a /= b  <=>  not (a = b)

through the law of excluded middle (if not in the intuitionistic logic).
Then:

   a > b \/ a = b  <=>  a >= b

So ">" and "/=" would carry the rest with.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de