[SCL] XML syntax options

[John F. Sowa]

Murray,

I think that we agree on what XML and MathML are,
but we are using the word "semantics" differently.

The excerpt you quoted says exactly what I said:
MathML has no semantics -- i.e., it knows nothing
about the meaning of any mathematical expression.
The only thing it can do is specify the syntax:

 > The intent of the content markup in Mathematical
 > Markup Language is to provide an explicit encoding
 > of the _underlying_mathematical_structure of an
 > expression, rather than any particular rendering
 > for the expression.

Nota bene:  structure = syntax, not semantics.

 > My point in this is that we *can* use MathML if our
 > definitions of the things we'd use in MathML are
 > defined identically, otherwise we can't...

As I said before, they don't specify what any
expression means -- i.e., the conditions for a
statement to be true or false or the value of
an expression, such as 2+2.

SCL is first and foremost a *semantic specification*
for an open-ended variety of different kinds of syntax.
We could just adopt the MathML syntax and use the SCL
semantics to give it some meaning.

 > That's because MathML's purpose is not to supplant
 > formatting languages, it's to express mathematical
 > formulae for both processing and presentation....

I understand that point very, very well.  But that is
no reason for it to have a unreadable, unwritable,
verbose syntax.  The Bell Labs syntax can be used
equally well for formatting and for processing.

 > In MathML, you explicitly say things like "x is equal
 > to negative b plus or minus the square root of b squared
 > minus 4 times a times c, divided by 2 times a".

Your quoted expression is the kind of notation I would like
to write.   But that is not MathML.  The web pages you cited
specify a notation that is very different from what you wrote.

 > XSLT wasn't designed to solve that problem. For what
 > it was designed for, it is a lifesaver.

I agree that XSLT is useful for many applications.

 > The solution you suggest only works in web browsers that
 > are hardwired to understand those specific HTML character
 > entities *and* have the necessary font support.

All modern browsers have the necessary font support.
The only ones that don't come from an obsolete technology
company in Redmond, Wash.  And by the way, MathML requires
the same fonts used for the HTML character entities.

John