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Re: [XQueryX] reuse MathML Content Markup to represent XQuery in XQueryX

From: David Carlisle <davidc@nag.co.uk>
Date: Wed, 9 Mar 2005 00:42:31 GMT
Message-Id: <200503090042.AAA07247@penguin.nag.co.uk>
To: franktang@gmail.com
CC: www-math@w3.org, public-qt-comments@w3.org



> Is XQuery powerful enough to query mathmatic information which markup
> by MathML Content Markup.

yes although a language designed for querying the xml structure is
clearly not optimal for doing such queries. You'd like to be able to
query modulo many relations that are not explict in the XML, such as
commutativity of certain operators.

> For example, if someone store two matrix (A - 3x5 and B- 5x4) by using
> MathML Content Markup. Is XQuery power enough to produce the output a
> 3x4 matrics C in MathML Content Markup that  C = A x B ?

Yes it could do that, which might be an interesting exercise, but it
would be easier (and probably more generally useful) if you wrote a
query or xslt to convert them to maple or mathematica (or similar
systems) for which matrix multiplication over mathematical types is a
primitive operation. If your Content mathml matrices are over the
integers coding the rules for a product would be simple enough in
xquery, but if the matrices are over some other number field such as the
complex numbers or a prime field, or just had symbolic entries, you'd
also have to encode the underlying arithmetic in Xquery which would
start to become a pain.

> How about predicate logic, If I have two element of content E and F
> E use MathML content Markup to express
> { (x) | -2 <= x <=3}
> and
> F use MathML content Markup to express
> { (y) | -4 <= y <=5}
> Is XQuery power enogh to perform a G = E & F
> to express a MathML content markup which express
> { (x, y) | ( -2 <= x <=3) && (-4 <= y <=5)}

this just involves syntactic re-arrangement of the terms (as you have
demonstrated) so doesn't require any computation and could fairly easily
be done in xquery.

> 
> ?

Neither seems to have any connection with the question in the subject
line.

David

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Received on Wednesday, 9 March 2005 00:42:59 GMT

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