Artificial Intelligence and Soft Computing: Behavioral ... - Arteimi.info

18.4 Semantic Interpretation by Case Grammar
and Type Hierarchy
The parse tree we constructed by ATN can be semantically interpreted [3] by
using case grammars [2] and type hierarchy. A type hierarchy describes a
subsethood relationship between the child and its parent in the hierarchy. In
other words, the parent nodes are more generic than the children. It has
similarity with lattice diagrams [1], where there exists a lower bound and
upper bound to such hierarchy and a strict relation to construct the hierarchy.
The ‘type hierarchy’ is useful for constructing knowledge about verbs and
their object space, if any, or to determine the meaning of a noun or verb, from
the generalized and specialized events / items in the hierarchy. For
demonstrating the concept of hierarchy, we consider the animal kingdom.
event
act
T
entity
Animals
Mammals Birds
⊥
event
The verbs in the type hierarchy have a significant role for interpreting
the semantics of an ATN. We thus use case grammars to describe the actions
of an agent by an instrument. For instance, the verb ‘laugh’ can be described
as an action of an agent by his lips to give himself and others enjoyment. Thus
we can represent laugh as a case frame as presented below in fig. 18.16.
act
Cries cow dog person cuckoo Lips Laughs
Fig. 18.15: The type hierarchy for the animal kingdom.