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Re: Happiness



> Date: Fri, 10 Jun 2011 21:20:23 +0200
> From: Ulrich Kulisch <Ulrich.Kulisch@xxxxxxxxxxx>
> To: Dan Zuras Intervals <intervals08@xxxxxxxxxxxxxx>
> CC: stds-1788@xxxxxxxxxxxxxxxxx
> Subject: Happiness
> 
> Dan,
> 
> suppose you walk in the street and a very beautiful but poor lady asks 
> you to give her a dollar. Generously as you are, you give her two and 
> the lady is happy.

	Ulrich,

	You need not entice me with a beautiful lady in need of my
	help.  I have given dollars even to rummy old men under
	similar circumstances.

	But using your words: The lady 'asks' & I 'generously give'.
	It is a voluntary act.  And given the choice, it is one that
	is easy to make generously.

	But suppose I was not given the choice.  Suppose it was
	mandated by law that one must give a dollar to anyone who
	demands it.

	I am just ornery enough that I think I would make the choice
	to avoid people on the street altogether rather than be forced
	to participate in a state mandated give away of my money.

> 
> If you give me the interval operations however nicely they are made I 
> would be happy. The lower and the upper bound of the result of an 
> interval operation performed for two reals give me what motion 24.03 
> requires.

	I know Ulrich.  And I'm sorry.  It is something you have been
	seeking since even before we met lo those many years ago.
	Indeed, such a thing already exists in one form or another
	on most machines today.  We could not say that before 754.

	Still, I would much rather be asked by a beautiful lady than
	forced by a faceless state.

> So mandating the operations with directed roundings cannot be a barrier 
> to acceptance of 1788.
> 
> Best wishes
> Ulrich
> 

	Perhaps.  Perhaps not.

	It depends on what people like those at Intel think you are
	mandating.

	If they think it is those operations they already provide
	through the use of rounding modes, then they will not give
	it another thought.  (Nor should we, for that matter.)

	But if they think you are demanding that they change their
	instruction set architecture to require static directed
	rounding instructions, then I think they will not give 1788
	another thought.

	They too still want to be able to choose.

	We can but try to help them choose wisely.


				   Dan