Subject: Re: set.lisp redefines POWERSET / {} for sets
From: Richard Fateman
Date: Wed, 05 Mar 2003 18:40:06 -0800
Overloading notation is very tricky. I don't agree
that you should use up all the operators for the
most elementary common use. Mathematica does this
(though not necessarily the most common usage). One
way out of this is to allow unicode or another nearly
unbounded set of operators, but that has its own problems
too.
RJF
Andreas J. Guelzow wrote:
> On Wed, 2003-03-05 at 11:06, Richard Fateman wrote:
>
>>Using {} for sets would mean that no one could
>>use it for anything else. This leads to difficulties.
>>
>>You may think it is standard to do {a,b,c} but
>>what about
>>{x in Z | prime(x) and x< 100}
>>which also standardly uses {} but also |.
>
>
> One of the (few) nice things about mupad is that it in fact allows both
> {a,b,c} and a variant of {x in Z | prime(x) and x< 100} namely:
> {2*i $ i=1..10}
> So this does not need to be exclusive.
>
>
>>{} () [] are also used in various combinatorial
>>notations.
>>
>>"standard" math notation must be evaluated
>>very carefully. It tends to be ambiguous
>>without context.
>
>
> But this still allows the argument that the most rudimentary use should
> be the default one. We consciously overload certain notation in various
> discipline but the base notation is usually the same.
>
> Andreas
>