As a very Dutch example, we describe cross serial dependencies, a phenomenon elaborately discussed by  and many others since. This phenomenon deals with the type of construction that contains verbs triggering V-raising, thus obtaining sequences of NPs and Vs with crossing dependencies. In the example a subordinate clause is used to circumvent interaction with `Verb Second' in main clauses (see next section). The crossing dependencies are indicated by indices.
dat de voorzitter de ministers het voorstel hoorde bespreken
that the chairman the minister the proposal heard discuss (lit.)
that the chairman heard the ministers discuss the proposal
Following the analyses of  in Categorial Grammar, we can view the sentence-final verb cluster as a complex predicate derived by composition of its constituent verbs. Taking subcatlists in Phrase Structure Grammar to be the equivalent of the (curried) functions of Categorial Grammar (as discussed in ), the composition operation can be implemented by appending the subcatlists of the clustered verbs. More precisely, the subcatlist of the first verb must be appended to the second, which as a whole must be appended to the third, if present, etc. This in order to guarantee that the subcategorized for arguments of the lower verb can be found higher up.
It would be possible to add to the formalism an `append' operation as extra primitive operation on feature structures (this is the approach taken in [p. 48]hpsg), but the effect can be achieved directly with difference lists ([pp. 126-128]pereira-shieber). This is done in the following annotated rule.
Figure 2 illustrates this rule in terms of Prolog lists.
In the lexicon the subcatlists of verbs all show a tail variable (`subcat out') unified with the end of the list. This technique makes it possible to have an unlimited number of raising-verbs, the subcatlists of which will all be appended to yield the right assignment of argument to verbs.