Paraconsistent Assertions

Abstract. Classical logic predicts that everything (thus nothing useful at all) follows from inconsistency. A paraconsistent logic is a logic where inconsistency does not lead to such an explosion. We argue that paraconsistent logics are especially advantageous in order to deal with assertions made by intelligent agents. Other propositional attitudes like knowledge and beliefs can in principle be treated along the same lines. We propose a many-valued paraconsistent logic based on a simple notion of indeterminacy. The proposed paraconsistent logic has a semantics that extends the one of classical logic and it is described using key equalities for the logical operators. A case study is included. We briefly compare with logics based on bilattices. We finally investigate how to translate the paraconsistent logic into classical predicate logic thereby allowing us to make use of automated deduction of classical logic in the future. We base our initial translation on recent work by Muskens. Our final translation is polynomial in the size of the translated formula and follows the semantics for the paraconsistent logic directly. The major motivation behind paraconsistent logic has always been the thought that in certain circumstances we may be in a situation where our information or theory is inconsistent, and yet where we are required to draw inferences in a sensible fashion... Numerous examples of inconsistent information/theories from which one might want to draw inferences in a controlled way have been offered by paraconsistent logicians. For example: 1. information in a computer data base; 2. various scientific theories; 3. constitutions and other legal documents; 4. descriptions of fictional (and other non-existent) objects; 5. descriptions of counterfactual situations. The first of these is fairly obvious..

Preliminary experience on safety of regorafenib after sorafenib failure in recurrent hepatocellular carcinoma after liver transplantation

Regorafenib is one option for second-line treatment of hepatocellular carcinoma (HCC), improving overall survival (OS) of sorafenib-tolerant patients who develop progression. We aim to evaluate safety and outcomes of regorafenib as second-line treatment for HCC-recurrence after liver transplantation (LT). This is a retrospective, multicentre, international study including regorafenib-treated LT-patients (2015-2018), with analysis of baseline characteristics and evolutionary-events during sorafenib/regorafenib treatment. Twenty-eight LT patients (57 years, 7% cirrhotics, 54% performance-status 1) were included. Median time from LT to regorafenib initiation was 3.9 (1.1-18.5) years; median time on sorafenib was 11.3 (0.7-76.4) months and 14 (1-591) days from sorafenib discontinuation to regorafenib. During regorafenib (6.3 months), all patients had at least 1 adverse event (AE), the most common grade 3/4 AEs were fatigue (n= 7) and dermatological reaction (n= 5). While no liver rejection was observed, plasma levels of immunosuppressive-drugs increased in 5. Twenty-four patients developed progression (38% extra-hepatic growth, 33% new extra-hepatic lesions/vascular invasion). Median OS from regorafenib initiation was 12.9 (95%CI:6.7-19.1) and 38.4 months (95%CI:18.5-58.4) for the sorafenib initiation. This is the first study showing safety of regorafenib after LT, thus providing the rational of considering regorafenib in the clinical decision-making in sorafenib-tolerant patients with HCC-recurrence after LT