Each grammar rule of this type needs to define two special '->' associations in its template:

cont_ is the locational qualifier. This is also just an ordinary noun phrase. This is the "the table" part in "the book on the table".

prep_ is the preposition production. This should be *or* contain a LocationTypeProduction match, which tells us the type of containment relationship specified by the grammar. *Alternatively*, you can define locType directly on this production. This specifies a LocType object giving the containment relationship.

class LocationalProduction :   Production