expand and _predicate_

We’ve already seen expand and _predicate_. Both can be used with variables.

Cherie Nowlan has directed movies, including the quirky Australian romantic comedy Thank God He Met Lizzie, but hasn’t acted in any movies. So a query that expands all the predicates from Cherie Nowlan will at best have name and director.film.

If the variable held the predicates from a director who had also acted, the possible set of expanded edges would be different.

Endpoint: /query