I recently read an article explaining how to get OWL like reasoning on an LPG store in neo4j using GraphScale. But I am very unclear on how to define OWL like rules on an LPG graph in the first place. Can someone please explain it to me?
I'm not very familiar with Graphscale. I would expect it to use standard OWL or RDFS ontologies, but if you're interested in complete reasoning capabilities your best choice is to reach out to our Derivo friends.
Now if a limited but more pragmatic approach could work for you, you may want to give the neosemantics extension a try. The latest release (126.96.36.199) includes some basic steps in this direction. It's quite embryonic at this stage, but if you have a look and you'll find a set of procedures under semantics.inference.
Keep an eye on https://jbarrasa.com/ for updates on this front and examples of use.