Semantic of the language

Hi everybody,

Last telcon we said that we were going to talk about the semantics of the
language.

Hopefully you all have the chance to look at these two papers:

[1] The Expressive Power of SPARQL
http://www.dcc.uchile.cl/~cgutierr/papers/expPowSPARQL.pdf

[2] Translating SQL Applications to the Semantic Web
http://userweb.cs.utexas.edu/~jsequeda/sql2sw_dexa2008.pdf

[1] states that SPARQL and non-recursive safe Datalog have the same
expressive power. [2] shows FOL rules, which can be implemented in Datalog
in order to automatically generate a rdf schema or owl ontology from a rdb
schema. There have been several concerns that the mapping language shouldn't
be more expressive than SPARQL. Given this previous work, if we define the
mapping language based on non-recursive safe datalog (as shown in [2]), then
we can assure that it will have the same expressive power of SPARQL [1].
Once we define the semantics, organizing the syntax should be
straightforward.

Looking forward to our conversation on tuesday.

Juan Sequeda
+1-575-SEQ-UEDA
www.juansequeda.com