https://cljdoc.org/d/datalevin/datalevin/0.10.7/doc/transaction#transaction-functions-in-datalog-store
> :db.fn/call is another way to call a transaction function, which does not store the function in the database, so this is usable in embedded mode, where that function is available in user code to call and that function can be a regular Clojure function.
Just one example would go a long way here.
> For usage examples, see tests in datalevin.test.transact.
Could this be a https://github.com/datalevin/datalevin/blob/d98b0946acfa5f5d8ffdf21eaefebeb219a33760/test/datalevin/test/transact.clj#L35?
PR welcome