The content of a verb is represented in HPSG by a feature structure of type psoa, which is structured as in hpsg2.
As indicated, the value of the nucleus feature is a
qfpsoa. This type is divided into subsorts corresponding to
particular semantic relations, each defined for appropriate semantic
roles which pick out either referential indices or psoas. The
only subsort of qfpsoa which pollard_sag:94 investigate
in any detail is that of verbs which take controlled complements, for
which controller assignment is argued to be based (following
Jackendoff jack:72) on semantic roles. The subsorts are
defined as indicated in Figure 2.1. Semantic arguments are
associated to syntactic arguments of the word introducing a relation
via structure sharing between the indices of the semantic arguments of
the relation and of elements on the word's subcategorisation list
(synsem 
local category subcat).
Figure 2.1: A part of the HPSG sort hierarchy for semantic relations
An example of the content nucleus value of the sentence They
persuaded me to leave can be seen in hpsg3. This
representation includes reference to a qfpsoa, leave,
which is not specified in the hierarchy in Figure 2.1, but
which can be viewed as a one-place relation which specifies that a
leaver leaves. The structure sharing between the
influenced value and the leaver value is achieved by the
HPSG control theory.
