Continuing with the simplified example presented so far, we can for instance define the tree family for verbs taking a nominal subject, a nominal object, and an indirect nominal object (i.e., ditransitive verbs) as follows: The trees generated for such a family will, among others, handle the following contexts: 25 It is straightforward to extend the grammar with new families.
for instance, Equation (42) shows how to define the transitive family (for verbs taking a nominal subject and a nominal object) and Equation (43), the intransitive one (alternatives of a verb sub-categorizing for a nominal subject).