The physical attributes of a person can be represented as in Fig. 9.
Fig. 9 A Semantic Network
These values can also be represented in logic as: isa(person, mammal), instance(Mike-Hall, person) team(Mike-Hall, Cardiff)
We have already seen how conventional predicates such as lecturer(dave) can be written as instance (dave, lecturer) Recall that isa and instance represent inheritance and are popular in many knowledge representation schemes. But we have a problem: How we can have more than 2 place predicates in semantic nets? E.g. score(Cardiff, Llanelli, 23-6) Solution:
- Create new nodes to represent new objects either contained or alluded to in the knowledge, game and fixture in the current example.
- Relate information to nodes and fill up slots (Fig: 10).
Fig. 10 A Semantic Network for n-Place Predicate
As a more complex example consider the sentence: John gave Mary the book. Here we have several aspects of an event.
Fig. 11 A Semantic Network for a Sentence