A sample HPSG lexical entry incorporating the representation as described above for the verb pay in the sense of John paid $100 to Mary can be found in Figure 2.14. The semantics expressed in this entry can be paraphrased as John acts on $100 with the effect that $100 goes to Mary's possession.
Figure 2.14: The lexical entry for the verb pay on the sense
expressed in John paid $100 to Mary
I will briefly review what the various fields of this representation
correspond to. The phonological (phon) feature has as its
value the written word to which the entry corresponds, for lack of a
more precise phonological transcription. The synsem feature
contains the syntactic and semantic information associated with the
word being represented. Only the local information will be
relevant in this thesis, specifically the category and
cont (content) information. category includes the
head features of the verb, all of the features defining the
form of the verb and how it can be used (aux specifies whether
the verb is an auxilliary verb, inv specifies whether the verb
can appear in inverted form, mod contains verb modifier
information, prd specifies whether the verb is predicative).
The category also contains a marking feature which
indicates whether the verb is being used within a complementised
clause (see Pollard and Sag 1994, pp. 45-47), and the subcat
feature which has a list of synsem objects, corresponding to the
synsem values of the signs with which the verb must combine to
become ``saturated''. Here I use the notation ``NP'' as a
shorthand notation for the feature structure representing a noun
phrase, with an index value of 
, as shown in d95 for both
object- and event-referring NPs.
The cont (content) field has two features: the nucleus, containing the core of the semantic information, and quants, used in the HPSG treatment of quantification (see Pollard and Sag 1994, ch. 8). The value of the nucleus field in this work differs dramatically from what appears in Pollard and Sag's original HPSG work. The semantic representation described in this section is integrated into HPSG in this field.
The value of the nucleus feature reflects the semantic structure of the verb. It is of type sit-desc and as such is defined for an internal feature of type situation and an external feature of type ext-desc. For pay, the internal semantics is an event of type cause-poss-rel, a subsort of cause-eff-rel for which the thematic:effect is constrained to be a ch-poss-rel (as defined in example dav25). Here the entity which is affected by the causation and undergoes a change of possession, corresponding to the second NP on the subcat list of pay, is restricted to be an entity of type money. The first NP on the subcat list is tied to the causer (actor), and the third NP is associated with the location at which the money ends up. The external feature is not specified in the lexical entry for the verb, since this situational information comes from elements in a sentence other than those indicated on the subcat list of the verb.
