Schema, XSD (W3C) version

[Rob Beezer]

Does anybody use the XSD (pretext.xsd) version of the schema? I think this
would also be known as the W3C version.

It has always been inferior. The RELAX-NG version (our real/main version) can
condition on attributes, but a conversion to XSD then reports "choice between
attributes and children cannot be represented; approximating".

I only built the XSD version to feed the tool that made a schema browser for us.
Now that Jason S is providing a superior browser, we don't need it.

Worse, we are now incorporating the PreFigure schema. (Well, that is a "really
good thing" (tm) actually!) Since the PF schema has some identifiers that
duplicate PreTeXt identifiers (within the schema construction), we have to
include it in a way that breaks the XSD conversion.

So...I am going to halt making the XSD version. (It existence is leading my
assistant to some poor choices.) We can try bring it back but right now, I
think it means some sub-optimal modifications to the PF schema. Holler if this
creates a problem for you (or your tools).

Rob