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The system is intended to store propositions like, ``All gods are
present everywhere.'', ``All gods are present somewhere.'', ``Some
gods are present everywhere.'', ``No gods are present somewhere.'',
``Some gods are present somewhere.'', etc. These propositions surely
cannot be held together in a single belief system. But they should be
stored and talked about, just as such propositions exist in this
composition. One clear way to achieve the possibility of storing
multiple epistemologies and ontologies of this kind is to build a
database system that has distinct layers in its kernel. It should be
possible to have a layer where ground level propositions exist without
`interaction' between them, hence even contradictory or false
propositions can be stored. This layer therefore will not have
semantic constraints. Another layer that takes the propositional
`atoms' and combines them with semantic constraints to eliminate
contradictions so as to build a system that is implicitly
consistent. But even at this layer, it should be possible to combine
propositions to form a system without checking for consistency. After
all we harbor inconsistent belief systems and we need to engage in a
discourse about them. This requires that a second layer of the kernel
that builds the systems contains only constraints of logical
connectives (like `and', `or', `implies' etc.) without checking for
consistency. The kernel therefore needs another layer where
consistency is imposed.
Based on these requirements, I propose, we build a knowledge base with
component classes that can instantiate objects into three different
layers:
- Layer 1 of Well Formed Formulae (WFF):
- A comprehensive, flexible, and
extendable logical core layer to store well formed formulae that are
completely neutral to epistemologies and ontologies.
- Layer 2 of Implicitly Structured Systems (ISS):
- A mechanism to compose
the well formed formulae expressed in the above layers using logical
connectives, quantifiers, and modalities, propositional attitudes
etc. Consistency is implicit, but not explicitly imposed by the
system.
- Layer 3 of Consistently Structured Systems (CSS):
- Similar to the
second layer, but with explicitly imposed validity constraints
resulting consistent systems. All the consistent systems are
defined only in relation to an explicit set of semantic rules
internal to the system.
By composing the elements from Layer 1 while expressing the elements
of Layers 2 and 3, we can represent belief systems with varying
degrees of consistency without any conflicting interaction between
them, for each system can be instantiated as independent objects in
the knowledge base. Several such systems with independent semantics
can be stored in a single knowledge base or in a collection of
distributed systems over the Internet to form a semantic grid, to
express multiple epistemologies and ontologies. A meta-discourse
about the semantic matching or mismatching between structures can be
made possible by using them as the terms and the predicates from upper
ontology (Metatype level).
Next: Complexity Dimension
Up: The Architecture
Previous: The Architecture
Nagarjuna G.
2005-01-25