Invariant Synthesis for Incomplete Verification Engines

We propose a framework for synthesizing inductive invariants for incomplete verification engines, which soundly reduce logical problems in undecidable theories to decidable theories. Our framework is based on the counter-example guided inductive synthesis principle (CEGIS) and allows verification engines to communicate non-provability information to guide invariant synthesis. We show precisely how the verification engine can compute such non-provability information and how to build effective learning algorithms when invariants are expressed as Boolean combinations of a fixed set of predicates. Moreover, we evaluate our framework in two verification settings, one in which verification engines need to handle quantified formulas and one in which verification engines have to reason about heap properties expressed in an expressive but undecidable separation logic. Our experiments show that our invariant synthesis framework based on non-provability information can both effectively synthesize inductive invariants and adequately strengthen contracts across a large suite of programs

Evaluating automatic cross-domain Dutch semantic role annotation

In this paper we present the first corpus where one million Dutch words from a variety of text genres have been annotated with semantic roles. 500K have been completely manually verified and used as training material to automatically label another 500K. All data has been annotated following an adapted version of the PropBank guidelines. The corpus’s rich text type diversity and the availability of manually verified syntactic dependency structures allowed us to experiment with an existing semantic role labeler for Dutch. In order to test the system’s portability across various domains, we experimented with training on individual domains and compared this with training on multiple domains by adding more data. Our results show that training on large data sets is necessary but that including genre-specific training material is also crucial to optimize classification. We observed that a small amount of in-domain training data is already sufficient to improve our semantic role labeler

La enseñanza de la traducción especializada. Corpus textuales de traductores en formación con etiquetado de errores

This paper describes the method used in teaching specialised translation in the English Language Translation Master’s programme at Masaryk University. After a brief description of the courses, the focus shifts to translation learner corpora (TLC) compiled in the new Hypal interface, which can be integrated in Moodle. Student translations are automatically aligned (with possible adjustments), PoS (part-of-speech) tagged, and manually error-tagged. Personal student reports based on error statistics for individual translations to show students’ progress throughout the term or during their studies in the four-semester programme can be easily generated. Using the data from the pilot run of the new software, the paper concludes with the first results of the research examining a learner corpus of translations from Czech into English.En el presente trabajo se describe el método que se ha seguido para enseñar traducción especializada en el Máster de Traducción en Lengua Inglesa que se imparte en la Universidad de Masaryk. Tras una breve descripción de las asignaturas, nos centramos en corpus textuales de traductores en formación (translation learner corpora, TLC) recopilado en la nueva interfaz Hypal, que se puede incorporar en Moodle. Las traducciones realizadas por los alumnos se alinean de forma automática (con posibles modificaciones) y reciben un etiquetado gramatical y un etiquetado manual de errores. Es posible generar de manera sencilla informes sobre los alumnos con información estadística sobre errores en las traducciones individuales para mostrar su progreso durante el cuatrimestre o el programa completo. En función de los datos obtenidos en la prueba piloto del nuevo software, este trabajo presenta los primeros resultados del estudio a través de un corpus de traducciones de aprendices del checo al inglés