In general, disjunction is considered to add expressive power to propositional logic programs under stable model semantics, and to enlarge the range of problems which can be expressed. However, from a semantical point of view, disjunction is often not really needed, in that an equivalent program without disjunction can be given. We thus consider the question, given a disjunctive logic program ,...

The aim of the present work was to examine in human lymphocytes, firstly, whether in vitro gamma-rays as compared with X-rays also induce chromatid malsegregation and at higher frequencies than chromosome loss and, secondly, whether the cytokinesis-blocked micronucleus assay combined with fluorescence in situ hybridization might be useful for the biomonitoring of individuals exposed to ionizing...

The question as to whether the propositional logic of Heyting, which was a formalization of Brouwer's intuitionistic logic, is finitely many valued or not, was open for a while (the question was asked by Hahn). Kurt Gödel (1932) introduced an infinite decreasing chain of intermediate logics, which are known nowadays as Gödel logics, for showing that the intuitionistic logic is not finitely (man...

Modal dependence logic (MDL) was introduced recently by Väänänen. It enhances the basic modal language by an operator =(·). For propositional variables p1, . . . , pn the atomic formula =(p1, . . . , pn−1, pn) intuitively states that the value of pn is determined solely by those of p1, . . . , pn−1. We show that model checking for MDL formulae over Kripke structures is NPcomplete and further co...

The logics treated here are the intermediate propositional logics of the form LJ + Ni(a), where Ni(a)’s are axioms of only one variable studied in Nishimura [6]. As is easily seen, the problem of the disjunction property of LJ+Ni(a) starts from i = 10 and the case of odd i can be trivially neglected. The case of i = 10 was solved by Kreisel and Putnam [5] and other cases except i = 14 were solv...

Biogeographical patterns within the California Floristic Province have been greatly affected by geological and climatic events. Here, we investigate the phylogeography of foxtail pine (Pinus balfouriana) in an effort to date its range disjunction using molecular data and to further our understanding of phylogeographical patterns for plants within the California Floristic Province. The distribut...