Answer Set Programming with External Sources

Answer Set Programming (ASP) is a well-known problem solving approach based on nonmonotonic logic programs and efficient solvers. To enable access to external information, HEX-programs extend programs with external atoms, which allow for a bidirectional communication between the logic program and external sources of computation (e.g., description logic reasoners and Web resources). Current solvers evaluate HEX-programs by a translation to ASP itself, in which values of external atoms are guessed and verified after the ordinary answer set computation. This elegant approach does not scale with the number of external accesses in general, in particular in presence of nondeterminism (which is instrumental for ASP). Hence, there is a need for genuine algorithms which handle external atoms as first-class citizens, which is the main focus of this PhD project. In the first phase of the project, state-of-the-art conflict driven algorithms were already integrated into the prototype system dlvhex and extended to external sources. In particular, the evaluation of external sources may trigger a learning procedure, such that the reasoner gets additional information about the internals of external sources. Moreover, problems on the second level of the polynomial hierarchy were addressed by integrating a minimality check, based on unfounded sets. First experimental results show already clear improvements

Masculine generic pronouns: Investigating the processing of an unintended gender cue

Contains fulltext : 228989.pdf (publisher's version ) (Open Access)Grammatically masculine words are often used when talking about people in general. In Dutch you would say that everyone was eating his lunch (‘iedereen was zijn lunch aan het eten’), even if the group consisted of men as well as women. This use of masculine words for generic reference was at the core of this dissertation. A series of experiments tested if Dutch masculine pronouns such as zijn ‘his’ and hij ‘he’ lead to a male bias during reading, even though they are intended to be interpreted generically. In other words, do we think of the group of people eating their lunch as predominantly male? Three eye-tracking experiments and one sentence evaluation experiment tested if the possessive pronoun zijn ‘his’ lead to a male bias. The results showed that men often experience a male bias, but women do not. A self-paced reading experiment testing generically-intended hij ‘he’ revealed a male bias for both women and men. These five experiments taken together show that the generic or “gender-neutral” use of masculine pronouns often makes only men visible and excludes others. A sixth experiment sheds light on a different context in which zijn ‘his’ is used to refer to women. The pronoun can be used to refer to women beyond generic contexts in the Limburgian dialect spoken in the Netherlands. For example, a sentence such as Mary is eating his lunch can mean that Mary is eating her own lunch in Limburgian. An acceptability judgement task showed that this interpretation is indeed possible in Limburgian, but not in Dutch.Radboud University, 21 januari 2021Promotor : Hoop, H. de Co-promotores : Swart, P.J.F. de, Frank, S.L.241 p