Truth-depressing hedges and BL-logic
We show a complete axiornatization of unary connectives interpreted by monotone and superdiagonal truth functions, so-called truth-depressing hedges. These connectives formalize linguistic hedges like "slightly true" and "more or less". We follow ideas of [P. Hdjek, On very true, Fuzzy Sets and Systems 124 (2001) 329-333] and show that BL(vt)-logic can be enriched by a unary connective for which we can establish strong completeness with respect to the desired interpretation. (c) 2006 Elsevier B.V. All rights reserved.
truth-depressing hedge bl-logic axiomatization fuzzy logic