[Om] Lots of our CDs (mostly the experimental ones) don't have a CDBase

Christoph Lange ch.lange at jacobs-university.de
Fri Jul 22 19:03:39 CEST 2011


Hi David, hi Paul,

I got the information that the CDBase is mandatory from the standard
section 4.2 "abstract CDs":

A Content Dictionary consists of the following mandatory pieces of information:
…
7. A CD base which, when combined with the CD name, forms a unique
identifier for the
Content Dictionary. It may or may not refer to an actual location from
which it can be
retrieved.

That clearly does not suggest that the CDBase is optional (and
defaulting to http://www.openmath.org/cd) – in contrast to what the
standard says about symbols.

BTW note (I should file this observation as a ticket!) that the
standard doesn't get the point clear when talking about symbols. The
description of the abstract OM object syntax (sect. 2.1.1) says that
the CDBase [of a symbol] is optional, without mentioning a default
value. The default is only mentioned in sect. 3.1.2 in the context of
the XML syntax – which is a bad way of structuring the specification.

About the CDBase of a CD my opinion is that we should not make it
default to http://www.openmath.org/cd, as the requirements are
different from writing OMOBJs.

* I think OMOBJs should be easy to write, and in most practically
occurring cases they involve using symbols from
http://www.openmath.org/cd – so it's reasonable to let them default.
* About CDs, on the other hand, I think it's worth educating people to
write semantically correct CDs. People getting started with writing
CDs will most likely copy an example from openmath.org. If the latter
don't declare an explicit CDBase (due to a default), people won't
declare a CDBase in their own CDs either, which will lead to the
production of a lot of CDs that claim (due to the default of which the
people are not aware) to come from the openmath.org domain – which
they are not.

So I think I will (maybe rather tomorrow than today):

* add CDBases to all CDs in www/cdfiles2/cd
* add a check for CDBase to the validation XSLT

… but in addition to that we'd also need to fix the RelaxNG (if you
agree with my above reasoning).

Cheers,

Christoph

-- 
Christoph Lange, Jacobs Univ. Bremen, http://kwarc.info/clange, Skype duke4701


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