Re: [Om3] [Fwd: ISSUE-33 (statistical symbols): Kyle's Siegrist's request for new Content-MathML symbol]

[Paul Libbrecht]

Le 24-oct.-08 à 12:09, Professor James Davenport a écrit :

On Fri, October 24, 2008 8:07 am, Michael Kohlhase wrote:

there was a request for symbols in content MathML3, we should talk about what to do here from the CDs side. In particular, I know that binomial

coefficient is in combinat1, but what about the others?

I enclose the original message, since it's hard to understand otehrwise.

Here is what I would love to see added to Content MathML:

1. Binomial coefficient

As MK says, in combinat1

so we would make the whole of combinat1 in MathML-cd-group?

2. Permutation coefficient:  n(n -1)...(n - k + 1), usually
rendered P(n, k) or nPk or (n)k.

Personally, I've always written n!/k!, but if there's a call for it, I
could always add it to combinat1.

Looks like it's common so it's probably needed in combinat1.

3. A probability operator with an optional "given" construction
(for conditional probability).  Typical rendering would be
   P(A, B, ...) (without conditioning) or  P(A, B, ... | C, D, ...)
(with conditioning).

For the monadic versions P(A), or P(A|C D ...) I have no problem: I assume their absence is due to the fact that we never had a probabilist on board

in OM. I assume the proposers P(A, B, ...) is P(A&B&...), and we MIGHT
want to see that represented explicitly.

I've never seen the "," sepped version (though been TA in such branch, shame on me!).

4. An expected value operator with an optional "given" construction
(for conditional expected value).  Typical rendering would be E(A,
B, ...) (without conditioning) or  E(A, B, ... | C, D, ...) (with
conditioning).

Again, I hace no problem with E(A) or E(A|C ...).
I have no idea what is meant by E(A,B).

You can measure expectation on any event, can't you?

5. General union, to form the union of Ai over i = a to b, or the
union of Ai where i is in an index set I.  This would work just
like the sum construction, with a bound variable and with lower and
upper limits, or with a bound variable and with a condition.

I discussed this in Barcelona
(http://www.jem-thematic.net/files_private/Barcelona.pdf). As far as
MathML2 is concerned, I quoted
<apply> <union/> <bvar>i</bvar> <lowlimit>... </apply>

satisfactory, especially as in the summation case one can write
<OMS name="sum" cd="arith1"/>
Maybe we shou;d bite the bullet and have the equuivalent of sum.

Hence it seems as if we are in the general 'condition in MathML3' debate. For OpenMath I quoted 'big union on make_list' which I admitted was not as

Relayed to other topic.

paul

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