Response to AR3

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Dear Alexandre,

Thanks for your continued support of RIF, and for the use cases in support of equality.

May we list your implementation on the RIF implementations page:

http://www.w3.org/2005/rules/wiki/Implementations


Alexandre Riazanov wrote:
> Hi everybody,
> 
> I am working on prototype for semantic querying of relational databases
> (http://www.freewebs.com/riazanov/query_answering.pdf),
> and RIF BLD is envisaged as one of the input languages (TPTP, OWL 2, SWRL
> and Derivational RuleML are the others).
> Since (a branch of) the Vampire prover is currently the core of the system,
> it will essentially become a rule engine for BLD, supporting query
> answering.
> 
> The first implementation will simply convert BLD to TPTP, so it will be
> useable with all TPTP reasoners.
> Since it's basically just a Java API, the toolkit may be useful for purposes
> other than TPTP conversion:
> it will have a factory for the abstract syntax + JAXB-based parser/renderer.
> 
> All the software will be open source. I am expecting to publish an alpha in
> September.
>  
> Since the positive equality in BLD is still in danger, I would like to
> mention a couple of
> examples I came across recently, working on the RDB stuff.
> 
> Use case 1. Semantic querying requires semantic mapping of RDB schemas,
> e.g.,
> by linking the tables to application domain concepts and relations.
> Typically,
> a part of a schema is just a declaration of functional dependencies between
> attributes
> of tables. These can be easily expressed if our language allows equality,
> e.g.
> the following rule states that the table_person.name functionally depends on
> table_person.sin :
> 
> ?NAME1 = ?NAME2
>    :-
> And
>   (
>       table_person(sin -> ?SIN, name -> ?NAME1),
>       table_person(sin -> ?SIN, name -> ?NAME2)
>    )
> 
> 
> Such rules can be used by the reasoner for search space reduction, e.g, by
> contextual rewriting.
> 
> 
> Use case 2. Suppose we use several RDBs designed by different people for
> different purposes.
> The same entities can be represented differently in different DBs. For
> example, the same
> person can be identified with his SIN in one DB, and with a surrogate
> integer key in another DB:
> 
> person_for_sin(?SIN) # Person
>     :-
> db1.table_person(sin -> ?SIN, name -> ?NAME)
> 
> 
> 
> person_for_key(?KEY) # Person
>     :-
> db2.table_person(key -> ?KEY, sin -> ?SIN, name -> ?NAME)
> 
> 
> hasSIN(person_for_key(?KEY),?SIN)
>     :-
> db2.table_person(key -> ?KEY, sin -> ?SIN, name -> ?NAME)
> 
> 
> 
> 
> So, for cross-querying we absolutely need something like this:
> 
> person_for_sin(?SIN) = ?P
>    :-
> And(
>         ?P # Person,
>         hasSIN(?P,?SIN)
>       )
> 
> 
> Please note that these are just recent examples that are fresh in my mind.
> I have seen others.