Hi Jesus, I’m glad you found the article helpful!
- When I say here, I just mean in my ASP translation. It’s just a convenient way to show what constraints Grakn applies on them.
- Correct, you can apply “played” to 4 arguments, as long as each of the argument is mapped to a role. So you can declare “played” as a relationship and define 3 roles “player”, “match”, “team”. An instance of “played” could have 11 “player” entities and 0 “match”. This is just for convenience of representation and we noticed it simplifies things in some domains we are working on. We plan to support cardinality constraints so you can specify things like “exactly 1 team and 1 match and 11 to 14 players are allowed”.
- “body |- head” is what other graph databases use for this so we followed this unwritten convention. We are reviewing the syntax at the moment though.