On revising fuzzy belief bases

We look at the problem of revising fuzzy be­ lief bases, i.e., belief base revision in which both formulas in the base as well as revision­ input formulas can come attached with vary­ ing truth-degrees. Working within a very general framework for fuzzy logic which is able to capture certain types of uncertainty calculi as well as truth-functional fuzzy log­ ics, we show how the idea of rational change from "crisp" base revision, as embodied by the idea of partial meet (base) revision, can be faithfully extended to revising fuzzy belief bases. We present and axiomatise an oper­ ation of partial meet fuzzy base revision and illustrate how the operation works in several important special instances of the framework.