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Re: A Sum-like notation for iteration

  • To: mathgroup at
  • Subject: [mg102263] Re: A Sum-like notation for iteration
  • From: pfalloon <pfalloon at>
  • Date: Mon, 3 Aug 2009 05:46:46 -0400 (EDT)
  • References: <h53nt4$1fu$>

On Aug 2, 7:56 pm, c... at wrote:
> For a future version of Mathematica, a would like to suggest a Sum-like 2D
> notation for Table and related constructs. By this I mean, for exemple,
> that an expression like
> RawBoxes@RowBox[{UnderoverscriptBox["Table", RowBox[{"i", "=", "m"}], "n"],
>    RowBox[{"f", "[", "i", "]"}]}]
> could be interpreted as
> Table[f[i], {i, m, n}]
> and, of course, in full generality (and due embellishments for list
> iterators and steps). By using this notation, for example, I have been able
> to make some people understand Table with many iterators much more easily.
> Setting the Notation package aside (which I refuse to use) I think it is
> possible to do this in many ways (using MakeBoxes, CellEvaluationFunction,
> etc.), but I have not attempeted beyond 3 iterators.
> Carlos Cesar de Araujo
> Gregos & Troianos
> Belo Horizonte, MG, Brasil
> (31) 3283-1122

I for one would be *horrified* to see such constructs included by
default in the system. The whole point of using 2D inputs (for powers,
fractions, named special functions, sums, products, and so on) is that
they should be general constructs recognized universally.

And I'm not sure why you would refuse to use the Notation package? It
is designed to do exactly the type of thing you're proposing. If
you're having trouble using it, it would probably be (more) worthwhile
to post about what problems you're having with it rather than trying
to reinvent the wheel.


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