Most material below is ranked around the splittings of lattices of normal modal logics. These splittings are generated by finite subdirect irreducible modal algebras. The actual computation of the splittings is often a rather delicate task. Refined model structures are very useful to this purpose, as well as they are in many other respects. E.g. the analysis of various lattices of extensions, l...

In this paper, we propose a method for modeling concepts in full computation-tree logic with sequence modal operators. An extended full computation-tree logic, CTLS∗, is introduced as a Kripke semantics with a sequence modal operator. This logic can appropriately represent hierarchical tree structures in cases where sequence modal operators in CTLS∗ are applied to tree structures. We prove a th...

This paper presents a first step towards completeness-viacanonicity results for coalgebraic modal logics. Specifically, we consider the relationship between classes of coalgebras for ω-accessible endofunctors and logics defined by Sahlqvist-like frame conditions. Our strategy is based on conjoining two well-known approaches: we represent accessible functors as (equational) quotients of polynomi...

Higher dimensional automata (HDA) are a model of concurrency [5, 8] that can express most of the traditional partial order models like Mazurkiewicz traces, pomsets, event structures, or Petri nets. Modal logics, interpreted over Kripke structures, are the logics for reasoning about sequential behavior and interleaved concurrency. Modal logic is a well behaved subset of first-order logic; many v...

“ba:y?d” as a persian lexeme is interwoven with modality, a semantic category and therefore has a complicated and thought- provoking semantic nature. this paper uses evidence from persian to investigate the usage of this lexeme and some of its semantic and pragmatic aspects in this language. the results indicate that this lexical category can convey a wide range of modal meanings in different c...

In this paper, we consider the binary relations of negligibility, comparability and proximity in the set of all hyperreals. Associating with them the binary predicates N , C and P and the operators [N ], [C] and [P ], we consider a first-order theory based on these predicates and a modal logic based on these operators. We investigate the axiomatization/completeness and the decidability/complexi...

Genetic algorithms (GAs) are a class of stochastic optimization methods inspired by the principles of natural evolution. Adaptation of strategy parameters and genetic operators has become an important and promising research area in GAs. Many researchers are applying adaptive techniques to guide the search of GAs toward optimum solutions. Mutation is a key component of GAs. It is a variation ope...

It has been recognised that the expressivity of description logics benefits from the introduction of non-standard modal operators beyond existential and number restrictions. Such operators support notions such as uncertainty, defaults, agency, obligation, or evidence, whose semantics often lies outside the realm of relational structures. Coalgebraic hybrid logic serves as a unified setting for ...