next up previous
Next: Inference in a Semantic Up: Semantic Nets Previous: Semantic Nets

Representation in a Semantic Net

 

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:

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



dave@cs.cf.ac.uk