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RE: content mark-up: operators vs. relations?

From: Hugh J. Devlin <devlinh@nwu.edu>
Date: Wed, 10 Nov 1999 13:08:25 -0600
To: "David Carlisle" <davidc@nag.co.uk>
Cc: <www-math@w3.org>, <strotman@nu.cs.fsu.edu>
Message-ID: <000001bf2bae$f6cb84a0$36ba6981@devlin>
David and Andreas,

Thanks for your replies. Sorry, I am a non-member, and I'm guessing I'm
wondering about an issue that has been discussed to death in the member's
forum, but I'm still trying to understand this...

David,

If I understand your guess about the way things are going...

> The current best guess is that the restriction on not using <apply/>
> with `relation' elements will be dropped and so you will be able to
> uniformly use <apply/> (with reln being kept for largely historical
> reasons).

Wouldn't this strip apply of some of its power to capture semantics?
Will <apply> become like a open paren and <apply/> like a close paren,
generic in the sense of serving as a container for either functional or
relation expressions?
Will the MathML DTD enforce ideas like,
"The first child of apply must be a functional symbol, the first child of
reln must be a relational symbol"
or
"Relational expressions can contain functional expressions, but functional
expressions cannot contain relational expressions"?
Does the current thinking maybe go somewhere along the lines of: "For
convenience we want to build into MathML some of the most popular functional
and relational symbols, but we don't want to ham-string people by
classifying those symbols as relational or functional, so therefore we
really can't distinguish between functional and relational expressions in
MathML"?
In the practice of building math browsers & editors, does distinguishing
between relational expressions and functional expressions in the
representation turn out to be more trouble than it's worth? Will MathML
leave this distinction to context?

Any comments clarifying this would be appreciated.

Thanks again,
Hugh
Hugh J. Devlin
devlinh@nwu.edu
Received on Wednesday, 10 November 1999 14:10:21 GMT

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