FAQ Database Discussion Community

Backwards Chaining With Variables

I have been reading up about inference in Prolog/Datalog and while forward chaining seems fairly simple to grasp, I have some issues with backward chaining with any sort of complex example which isn't simply propositional or used to determine a true or false value. I was reading an article the...

what are the semantics of datalog and prolog?

Does datalog operate on sets or multisets? Does the same apply to prolog as well? I wasn't able to find any documentations on that.