SpiceDB is an open source, Google Zanzibar-inspired, database system for creating and managing security-critical application permissions.

SpiceDB

Hello, I need to create a permission with a complex set of unions and intersections.

Something like: 

```
definition sample/registration {
  relation learner: sample/student;
  relation target: sample/formation;

  permission subscribe = (target->subscribe & learner->subscribe) + learner->self
}
```

Is it possible to use parenthesis to priorize the operations ?

Otherwise, how can we do this kind of things in rebac ?

Thanks (sorry for the noob question !)