Complexity and Definability Issues in L∏1/2

摘要

In this work we investigate several complexity and definability problems for the logic L∏1/2. We show that the universal fragment of the theory of real closed fields can be faithfully interpreted in such a logic. Then we investigate the logics of t-norms definable in L∏1/2, and we prove that they are all in PSPACE. Finally we show that the most important fuzzy logics are complete with respect to classes of t-norms which are definable in L∏1/2.