Abstract The TPTP World is a well established infrastructure that supports research, development, and deployment of Automated Theorem Proving (ATP) systems. This work uses data in the TPTP World to assess progress in ATP from 2015 to 2023.

Meta-theoretical results on the decidability, generative capacity, and recognition complexity of several syntactic theories are surveyed. These include context-free grammars, transformational grammars, lexical functional grammars, generalized phrase structure grammars, and tree adjunct grammars.

Americanae nace como un proyecto conjunto que surge dentro de la Red Europea de Información y Documentación sobre América Latina (REDIAL), y que ha afrontado la Biblioteca de la Agencia Española de Cooperación Internacional para el Desarrollo (AECID). Esta nueva biblioteca virtual hace más accesibles los libros digitales de tema americanista a los investigadores y usuarios interesados de cualquier parte del mundo.

We develop intercalation lemmas for the computations of the top-down tree transducers defined by Rounds [15] and Thatcher [17]. These lemmas are used to prove necessary conditions for languages all of whose strings are of exponential length to be tree transducer languages. The language {ww:wε{a,b}*, ¦w¦=2n,n≥0}, which is generable by the composition of two transducers, is shown not to be generable by one. The proof technique applies to bottom-up transducers as well. The results are related to some subclasses of Woods' Augmented Transition Networks [18] characterized elsewhere in terms of tree transducer languages [14].