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Re: Samples from the Internet

From: David Carlisle <davidc@nag.co.uk>
Date: Mon, 27 Nov 2006 11:45:52 GMT
Message-Id: <200611271145.kARBjqK1027716@edinburgh.nag.co.uk>
To: juanrgonzaleza@canonicalscience.com
Cc: www-math@w3.org


> I am really confused.

You cited several parts of the spec, but you didn't really say what
parts of them you found confusing.

ci and csymbol can be used in the same places, and take the same
attributes and same content.

As you said ci is intended to denote more general identifiers, and
csymbol is intended to denote symbols with an external definition, but
the mathematical distinction between these two is not precise, and so
the usage of the two elements will display some personal (or tool)
preferences, especially as MathML1 only had ci so some tools may have a
preference for generating ci.

In general if you have 
f(x)
then you'd probably expect to use ci for f as a generic identifier, and
if you have
dx/dt
(and didn't want to use <diff/> for some reason) you'd expect to use
csymbol for diff.

But it depends on circumstances, if the math fragment is  in a book and
says on page one, let f denote Ramanujan's F-function.
http://mathworld.wolfram.com/Ramanujanf-Function.html
...
then you may want to use csymbol for f

Similarly if you are discussing various definitions of differential
operator over different domains, you may want to use <ci>diff</ci>
to refer to a generic reference to all of them (or at least one
unspecified one) It's just a matter of degree, and you can't really say
anything at all about the usage in a small fragment taken out of
context.


For both ci and csymbol, there is no requirement that the definitionURL
refers to any machine readable definition, so the extent to which you
can mechanically process content mathml depends on many more factors
than whether ci or csymbol is used in the markup. This is an essential
feature of any Mathematical encoding, not a weakness in MathML. If you
try to be complete then provably you can't express anything interesting.


David
Received on Monday, 27 November 2006 11:46:10 GMT

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