[tannhaeuser]

Datomic, though, isn't Datalog syntax at all.

I've got nothing against Datomic, but can't help to think learndatalogtoday is outright false advertising by trying to capture "Datalog" as SEO term for a proprietary graph database which has nothing to do with Datalog/Prolog.

The point of Datalog is that it's a subset of Prolog syntax, implying that engines can be reasonably exchanged for one another. But this is only possible with real Datalog, or SPARQL for that matter.