[ontoiop-forum] ontoiop_20150209: Chat Transcript

[Till Mossakowski]

*Chat transcript from room: ontoiop_20150209*
*2015-02-09 GMT-08:00*
*[07:58] **TillMossakowski: *please find the slides at
http://iws.cs.uni-magdeburg.de/~mossakow/Slides-OntoIOp.pdf
*[08:00] *anonymous morphed into FabianNeuhaus
*[08:01] **TillMossakowski: *anyone on Skype?
*[08:02] **TerryLongstreth: *I'm trying to get off of another
conference, will dial in shortly.
*[08:03] *anonymous morphed into Conrad
*[08:04] **ChristophLange: *Hi all, UML is not my field, but
@TillMossakowski I will look into Ontohub issue 1066 meanwhile.
*[08:11] **TillMossakowski: *Conrad: operations should not be subsumed
under the term "properties".
*[08:11] **TillMossakowski: *Alexander: why not stick to UML terminology
and speak of attributes and (query) operations?
*[08:12] **TillMossakowski: *Alexander: the parameters of the operations
are also of form tau[c]
*[08:14] **Alexander Knapp: *We should change the property declaration
into an operation declaration (for queries): c.o(x_1 : \tau_1[c_1],
\ldots, x_n : \tau_n[c_n]) : \tau[c'] for operations; c.p : \tau[c']
*[08:15] **TillMossakowski: *properties are just c.p : tau[c']
*[08:16] **TillMossakowski: *i.e. attributes
*[08:16] **TillMossakowski: *are multiplicities allowed in return values
of operations?
*[08:18] **Alexander Knapp: *Operations could have out or in-out
parameters; check whether this is possible also for query operations.
Check whether return parameters are unique.
*[08:21] **TillMossakowski: *compositions are separated from normal
properties, because they have a special semantics
*[08:22] **Alexander Knapp: *Stick with the current UML2 terminology.
*[08:25] **Alexander Knapp: *"A single parameter may be distinguished as
a return parameter" (UML Superstructure Specification 2.4.1, p. 123)
*[08:28] **TillMossakowski: *Composites are always binary. In
associations we do not cover composites, just specify the owner roles.
*[08:31] **Alexander Knapp: *Make it possible to have associations for
declaring two properties as inverses of each other.
*[08:37] **TillMossakowski: *The meta-properties should be better
explained in the document.
*[08:37] **Alexander Knapp: *Introduce "annotations" not for
classifiers, but for properties to make clear their intention.
*[08:40] **Alexander Knapp: *Choose different names for associations in
Fig. E.1.
*[08:48] **TillMossakowski: *Alexander: the semantics of an association
is a set of individuals (not of sets, bags etc.).
*[08:49] **TillMossakowski: *But if you have a binary association, and
fix one of the ends, you get a function with a type, and this type may
involve sets, bags etc.
*[08:50] **Conrad: *See semantics of associations in 11.5.3, especially
the paragraph beginning "For an Association with N memberEnds".
*[08:51] **Conrad: *From the UML spec: For an Association with N
memberEnds, choose any N-1 ends. Let the Property that constitutes the
other end be called oep, so that the Classifiers at the chosen N-1 ends
are the context for oep (see 9.5.3). Associate specific instances with
the context ends. Then the collection of links of the Association that
refer to these specific instances will identify a set of instances at
oep. The value represented by oep (see 9.5.3) is a collection calculated
from this set as follows: All of the instances in the set occur in the
collection, and nothing else does. If oep is marked as unique, each
instance will occur in the collection just once, regardless of how many
links connect to it. If oep is marked as nonunique, each instance will
occur in the collection once for each link that connects to it. If oep
is marked as ordered, the collection will be ordered in accordance with
the ordering information in the links. The cardinality of this
collection is its size. The multiplicity of oep constrains this
cardinality, or in the case of qualified associations, the size of the
collection partition that may be associated with a qualifier value.
*[08:51] **TillMossakowski: *hence, the semantics of associations is not
just a set of tuples, but also contains additional information giving
the order in the sequences etc. obtained in this way.
*[08:54] **TillMossakowski: *Fabian: the semantics could be defined as a
set of functions (say, from signals to tau[tracksetion] and vice versa)
that enjoy the property that each function leads to the same set of tuples.
*[08:56] **Conrad: *Confirming Till's comment "hence" above, from UML
spec: When one or more ends of the Association are ordered, links carry
ordering information in addition to their end values.
*[08:57] **TillMossakowski: *Alexander: the ordering in the lists that
you get are completely unspecified. Hence, you can get the projection
functions to list by just returning the set, arbitrarily converted to a list
*[08:59] **Conrad: *Conrad: The ordering of property values isn't
arbitrary. UML has actions for adding values at certain points in a
list. Getting values from a property will reflect the way they are added.
*[08:59] **Alexander Knapp: *Thanks, Conrad. We'll have to add at least
a comment to this effect.
*[09:01] **TillMossakowski: *where is buml:Sequence specified?
*[09:01] **TillMossakowski: *Conrand: this is probably a typo
*[09:02] **MichaelGruninger: *need to leave now ...
*[09:24] **TillMossakowski: *corrected slides:
http://iws.cs.uni-magdeburg.de/~mossakow/Slides-OntoIOp.pdf
*[09:27] **FabianNeuhaus: *sorry, I will have to go soon. I have some
new feature requests for DOL, but I do that on the email list
*[09:30] **Alexander Knapp: *Composite aggregation is a strong form of
aggregation that requires a part instance to be included in at most one
composite at a time (UML Superstructure 2.4.1, p. 38).
*[09:36] **TillMossakowski: *Conrad: one and the same track can own one
and the same signal through different composition relations. Hence, the
axiom on slide 13 can stay as it is.
*[09:43] **TillMossakowski: *p.16, last axiom: needs to be reformulated:
(r x z), and (member y z)
*[09:46] **TillMossakowski: *Fabian: use different variables for sets
and individuals
*[09:46] **Alexander Knapp: *Multiplicity constraints for composite
properties better without a special "!"
*[09:50] **Alexander Knapp: *Sorry, I have to leave, trying to catch my
train... Thanks for the comments!
*[10:06] **TillMossakowski: *We should try to complete the UML to Common
Logic translation until Feb 23. Then my student Martin Glauer will have
enough time to implement the translation into Hets before the OMG
meeting (which starts on March 23).
*[10:07] **TillMossakowski: *next meeting: Feb 23, same time. Topic is
third iteration of the UML to Common Logic translation.
*[10:07] *List of attendees: Alexander Knapp, ChristophLange,
ConradBock, FabianNeuhaus, MichaelGruninger, OliverKutz,
TerryLongstreth, TillMossakowski, MihaiCodescu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listserv.ovgu.de/pipermail/ontoiop-forum/attachments/20150209/0b6d9104/attachment.html>