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We present a software tool that is able to automatically translate an NP problem into a STRIPS problem such that the former problem has a solution iff the latter has one, a solution for the latter can be transformed into a solution for the former, and all this can be done efficiently. Moreover, the tool is built such that it only produces problems that belong to a fragment of STRIPS that is solvable in non-deterministic polynomial time, a fact that guarantees that the whole approach is not an overkill. This tool has interesting applications. For example, with the advancement of planning technology, it can be used as an off-the-shelf method to solve general NP problems with the help of planners and to automatically generate benchmark problems of known complexity in a systematic and controlled manner. Another interesting contribution is related to the area of Knowledge Engineering in which one of the goals is to devise automatic methods for using the available planning technology to solve real-life problems.

RESUMENPara entender el origen de la diversidad de los bosques de América Central, se necesita integrar estudios de plantas actuales y fósiles. En este trabajo, describimos fósiles de Humiriaceae, excavados de dos nuevas secuencias sedimentarias en la Península de Azuero, Panamá. Los fósiles fueron encontrados en depósitos marinos-marginales del Oligoceno (una localidad) y del Mioceno temprano (dos localidades). Describimos nuevos especímenes y aumentamos la descripción morfológica de Lacunofructus cuatrecasana Herrera, Manchester et Jaramillo para las localidades del Oligoceno y Mioceno temprano y presentamos un nuevo registro de Sacoglottis sp., para el Mioceno temprano. Estos nuevos registros expanden los rangos de distribución geográfica y temporal para ambos taxones, y además demuestran que la familia Humiriaceae fue un importante constituyente de los primeros bosques en América Central. La evidencia presentada también sugiere que hubo dispersiones de especies de Humiriaceae entre Centro y Sur América mucho antes del cierre del Istmo de Panamá. Se necesitan más estudios para establecer con claridad si el origen de Humiriaceae se dio en América Central o Sur América. ABSTRACTUnderstanding the origin of the diversity in Central American forests requires the integration of both extant and fossil taxa. Here, we provide a description of Humiriaceae fossils from two new sedimentary sequences in the Azuero Peninsula, Panamá. Fossils were recovered from Oligocene (one locality) and Early Miocene (two localities) marginal marine deposits. We describe new specimens and augment the generic description of Lacunofructus cuatrecasana Herrera, Manchester et Jaramillo, and present a new record of Sacoglottis sp. Our results expand the temporal and geographical distribution of both taxa and show that

Recently, it has been shown how to automatically translate any problem in NP, expressed in the language of second-order logic, into a STRIPS planning problem. In this work, we extend this translation by considering decision problems in the polynomial-time hierarchy (PH) and not just NP. Since decision problems in PH require in general exponentially-long “certificates”, the plans (if any) for the resulting STRIPS problems may have exponential length. Besides explaining the novel translations, we present experimental results and discuss the challenges that such problems pose.