[Om] OpenMath 2010

David Carlisle davidc at nag.co.uk
Fri Jul 16 11:30:06 CEST 2010

On 15/07/2010 23:07, Professor James Davenport wrote:

Some comments on the notes of the OM meeting (at which I unfortunately 
couldn't attend)

 > The old MathML-C)OpenMath is now known as p2s (Pragmatic)Strict).
 > As far as MK knows, the only remaining anomaly is over cdbase.

Actually the "pragmatic" terminology (although it appeared in one early 
draft of MathML3) has been removed from MathML.

 > Q. Why was DefinitionURL deprecated in MathML (by declaring it to be
 > pragmatic-only).

the notes don't record who asked the question, but it's not deprecated 
(you can't deprecate something that was never there) the attribute isn't 
in Strict MathML because it isn't in OpenMath.

MathML DefinitionURL in general (if it doesn't point to a CD) 
corresponds to an OpenMath annotation using a symbol "definitionurl" in 
some CD and a OMstring to hold the URI.  In the case that the 
definitionurl is of the form uri-of-cd#symbolname then it just 
corresponds to the usual OMS cd=... name=... attrbutes.

This rewrite is built into the MathML -> Strict rewrites, and so there 
will never be a definitionURL in the resulting strict MathML, so the 
schmea for Strict Content MathML doesn't need, and doesn't have, this 

 > In OpenMath, cdbase can be inherited from any parent, which is the
 > same as MathML. OpenMath defaults to http://www.openmath.org/CD, but
 > MathML says that it is inherited from the mathematics embedding
 > mechanism.

There is no difference between MathML and OpenMath here. In the  XML 
encoding of OM the OM standard says


If a symbol does not have an explicit cdbase
attribute, then it inherits its cdbase from the
first ancestor in the XML tree with one, should such an element

the "XML Tree" wording was not accidental, and it allows for this 
attribute to be inherited from outside the openmath elements from a 
containing document element, just as in MathML.

 > MK felt that we should work towards a new normative standard.

I think we should be _extremely_ cautious about doing that. After more 
than a decade we finally have OpenMath and Content MathML formally 
aligned and to do anything at this point to break that alignment before 
MathML3 is even standardised, but when it's too late in the process to 
change it if OpenMath changes would be extremely damaging. At most we 
could consider an editorial "second edition" which acknowledges the 
MathML3 work, and fixes a few typos etc, but we should not introduce an 
"OpenMath 3" that changes the OpenMath Object model or CD format.

It's not that OpenMath should never change, but having got MathML in 
sync, we should aim to keep them so, so any OpenMath3 should be 
synchronised with a matching MathML 4.

 > Q. Should there be a reference translator (Strict,OpenMath)?
 > A. DPC has such things

I don't think there needs to be a reference translator (we never had an 
official reference translator between xml and binary encodings for 
example) The current Cd presentation includes the translator, you'll see 
"strict content mathml" in the xhtml view even though the CD file only 
has OM.

 > OpenMath 3 Working Group.

as noted above I think we should be considering, at most, an editorial 
"second edition" at this time.


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