Example

A simple type hierarchy, with types needed to define the agent and the object of the action ``throwing'', is presented in Figure 2.1. A typed feature structure, describing a particular instance of the action ``throwing'', in which the agent (``thrower'') is of type index, third person, masculine, and singular, and the object (``thrown'') is of the same type, has the same person and number, but different gender, is presented in Figure 2.2. The types (feature values) are written in boldface lowercase, while the features (THROWER, THROWN, PERSON, NUMBER, GENDER) are in regular uppercase letters. The representation used in Figure 2.2 is known as an attribute-value matrix (AVM), but typed feature structures can also be represented as labeled directed graphs, as in Figure 2.3.

Figure 2.1: A simple type hierarchy.

Figure 2.2: A simple typed feature structure, represented as an AVM.

Figure 2.3: A simple typed feature structure, represented as a directed graph.