Reinforcing a Claim in Commonsense Reasoning

Logical Formalization of Commonsense Reasoning

Volume

Papers from the 2003 AAAI Spring Symposium

Contents

Formalizations of commonsense knowledge rely on highly simplified representations of the world. After a conclusion is justified on the basis of one such representation in a nonmonotonic logic, it may not remain valid when additional relevant facts are taken into account to bring the formalization to a closer approximation of reality. However, if the conclusion continues to hold in the enriched theory, we can consider it to be reinforced. An argument in support of a claim can be represented by a sequence of nonmonotonic theories, each containing and enhancing the previous theory in the sequence and each entailing the claim. This idea is illustrated here by a sequence of formalizations of "Sam’s Calculus -- an example of commonsense reasoning due to Ernie Davis -- in the language of the Causal Calculator.