- From: Mike Bergman <mike@mkbergman.com>
- Date: Fri, 17 Jan 2020 23:39:07 -0600
- To: semantic-web@w3.org
Hi Henry, The Patterson paper is an excellent intro to DL as well. A hearty thanks for this reference. I would be interested to see how extensions to OWL 2 might accomplish the 'typing' objectives noted by Patterson. Do you know of any efforts in that direction? Thanks! Best, Mike On 1/17/2020 5:51 PM, Henry Story wrote: > Hi, > > I came across Coherent Logic recently. Apparently it is > as expressive as First Order Logic. And I found that it was used > by Jos De Roo’s EYE implementation of an N3 reasoner. [1] > I was wondering what the feedback of its use was in the field, and > return on experience on how it fit into the Semantic Web stack. > > I came across it by reading an excellent 2017 paper by > Evan Patterson [2] > "Knowledge Representation in Bicategories of Relations” > > Where David Spivak (MIT) has put together some very elegant > work showing how Category Theory could be applied to Databases, > and in a number of articles tying these to RDF and SPARQL, the > problem has been that his Database instances are functors from > a small Category playing the role of a Schema into the Category Set, > where objects are Sets and morphisms are functions. This does > not fit well with RDF as many relations such as foaf:knows > are not functional. > > By adapting this functorial semantics and instead of using > normal Categories for Schemas, Patterson uses Bicategories of relations > which can have morphisms between morphisms (giving us > inference). Then when representing DB instances as functors > into the Category Rel, where objects are Sets and morphisms > are relations, we get much closer to RDF. > Indeed Patterson starts off his discussion with Description Logics. > > (Note by the way that both Spivak and Patterson, point to a > fundamental concept in Category Theory known as the Grothendieck > construction that takes a tabular database and turns it into > the flattened structure of RDF, this itself being essential in > analyses of SQL or SPARQL Queries) > > Now the first part of the paper shows that ”regular logic is the > internal language of bicategories of relations”. The final > section shows that ”distributive relational ontology logics (ologs)” > correspond to Coherent Logic. > > This way of putting things gives a special place to ”regular > logic” and ”coherent logic”. So I searched around and found > the latter used by Jos de Roo’s N3 reasoner EYE, which seems > to somewhat confirm Patterson’s modeling of RDF. > > > Henry Story > > [1] See Twitter thread https://twitter.com/bblfish/status/1215024256985247745 > [2] https://www.epatters.org/assets/papers/2017-relational-ologs.pdf > --
Received on Saturday, 18 January 2020 05:39:12 UTC