[Trac] [OpenMath] #15: sort out set/multiset in mcd examples

[OpenMath]

#15: sort out set/multiset in mcd examples
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     Reporter:  kohlhase    |          Owner:  jhd             
         Type:  proposal    |         Status:  assigned        
     Priority:  blocker     |      Milestone:  MathML3CD Draft1
    Component:  MathML CDs  |        Version:                  
   Resolution:              |       Keywords:                  
Include_gantt:  0           |   Dependencies:                  
   Due_assign:  YYYY/MM/DD  |      Due_close:  YYYY/MM/DD      
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Changes (by jhd):

  * status:  new => assigned

Comment:

 I feel some strategic questions here, as well as not really understanding
 the mcd format.
 (1) Are we going to go the OM way of set/multiset, or the MathML2 way with
 type=multiset?
 (2) The mcd currently says "Sets and lists can also be constructed by
 evaluating a function over a domain of application", whereas in OM this is
 (currently) done with map, not set. I believe there are good reasons for
 this.
 (a) set is n-ary (and commutative), map is binary and not commutative.
 (b) In mcd's view, what is
     set({{1,{1,10}},{2,{2,20}}},{1,2})?
     Since the first object is a set of ordered pairs, and hence a
 function, it could be either {10,20} or {{{1,{1,10}},{2,{2,20}}},{1,2}}.

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Ticket URL: <https://trac.kwarc.info/OM3/ticket/15#comment:4>
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The development of the OpenMath Standard and Content Dictionaries.