Semantic models are presented for two simple imperative languages with higher order constructs. In the rst language the interesting notion is that of second order assignment x := s, for x a procedure variable and s a statement. The second language extends this idea by a form of higher order communication, with statements c ! s and c ? x, for c a channel. We develop operational and denotational ...

The paper starts with an examination and critique of Tarski’s wellknown proposed explication of the notion of logical operation in the type structure over a given domain of individuals as one which is invariant with respect to arbitrary permutations of the domain. The class of such operations has been characterized by McGee as exactly those definable in the language L∞,∞. Also characterized sim...

Knowledge involves belief. Belief is a propositional attitude, i.e. an attitude that a subject holds towards a proposition. If a subject S knows that P and the proposition P involves no further knowledge attribution, let us say that S possesses first-order knowledge. On the other hand, if S knows that P and the proposition P involves a knowledge attribution, let us say that S possesses higher-o...

OBJECTIVE To compare how nurses in two different paper-based systems perceive the impact of a computerized physician order entry (CPOE) system on their medication-related activities. SETTING 13 non-surgical, adult inpatient wards in a Dutch academic hospital. METHODS Questionnaire survey of 295 nurses before and 304 nurses after the implementation of a CPOE system. These nurses worked with ...

We report on a collection of mites in the family Laelapidae associated with scarabaeid beetles in Iran. Five known species are recorded from Iran for the first time: Coleolaelaps asiaticus Karg, 1999, Hypoaspis integer Berlese, 1911, Hypoaspis pentodoni Costa, 1971, Hypoaspis phyllognathi Costa, 1971, and Hypoaspis terrestris (Leonardi, 1899). Four new species are described: Coleolaelaps costai...

We propose a simple but powerful approach to the verification of parameterised systems. The approach is based on modelling the reachability between parameterized states as deducibility between suitable encodings of states by formulae of first-order predicate logic. To establish a safety property, that is non-reachability of unsafe states, the finite model finder is used to find a finite counter...