[Om] Problems with the MathML CDGroup

[W Naylor]

Hi all,

at the end of last week Clare So (ORCCA - University of Western Ontario) 
was visiting The University of Bath. She has been involved in a project 
with the objective of translating between OpenMath and MathML. She has 
come across various problems in this work so we had a meeting on Thursday 
& Friday to discuss them. Many of the problems are on the MathML side and 
as such can be circumvented by using semantics or csymbol elements. I did 
identify a few omissions on the OpenMath side however. These are the 
following:

1/ The MathMLtypes CD is missing symbols for the 'multiset' and 
'matrix_row' types,
2/ The suchthat and map constructors (from set1) have no analogues in 
multiset.
3/ The suchthat operator in list1 is ambiguous, it gives no order on the 
items in the list to be returned (this of course does not matter for 
sets). I would suggest a new definition which had a signature:

suchthat
	S			(The set containing the elements)
	o: (S x S) -> Boolean	(an ordering on S)
	p: S -> Boolean		(the selector predicate)

it seems that MathML has an 'order' attribute in place of the ordering 
function I'm suggesting. This has 2 possible values, numeric or 
lexicographic (which it must be said has a range of interpretations!)

hopefully these CDs can be ammended,

all the best,

Bill

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-                  Dr. W.A. Naylor
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-                  http://www.cs.bath.ac.uk/~wn
-                  http://orcca.on.ca/~bill
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-                  work tel: +44 1225 386183
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