Constructive Discursive Reasoning

摘要

Discursive reasoning is based on the nature of our ordinary discourse. Namely, several participants exist and have some information, beliefs, and others. Then, truth is formalized by means of the sum of opinions supplied by participants in discursive reasoning. Even if each participant has consistent information, some participant could be inconsistent with other participants. We propose a constructive discursive logic with strong negation CDLSN based on Nelson's constructive logic N- as a refinement of Jaskowski's discursive logic. We give an axiomatic system and Kripke semantics with a completeness proof. We also discuss some applications in decision making.