Extending tolog by Lars Marius Garshol.
Abstract:
This paper describes a number of extensions that might be made to the tolog query language for topic maps in order to make it fulfill all the requirements for the ISO-standardized TMQL (Topic Map Query Language). First, the lessons to be learned from the considerable body of research into the Datalog query language are considered. Finally, a number of different extensions to the existing tolog query language are considered and evaluated.
This paper extends and improves on earlier work on tolog, first described in [Garshol01].
As you can see from some recent post here, Datalog research continues!