We show that a set has an η-representation in a linear order if and only if it is the range of a 0'-computable limitwise monotonic function. We also construct a Δ₃ Turing degree for which no set in that degree has a strong η-representation, answering a question posed by Downey.

Shortest possible axiomatizations for the implicational fragments of the modal logics S4 and S5 are reported. Among these axiomatizations is included a shortest single axiom for implicational S4—which to our knowledge is the first reported single axiom for that system—and several new shortest single axioms for implicational S5. A variety of automated reasoning strategies were essential to our discoveries.

Urquhart and Méndez and Salto claim to establish completeness theorems for the system C and two of its negation extensions. In this note, we do the following three things: (1) provide a counterexample to all of these alleged completeness theorems, (2) attempt to diagnose the mistakes in the reported completeness proofs, and (3) provide complete axiomatizations of the desired systems.

Certain distributivity results for Lukasiewicz’s infinite-valued logic Lℵ0 are proved axiomatically (for the first time) with the help of the automated reasoning program Otter [16]. In addition, non -distributivity results are established for a wide variety of positive substructural logics by the use of logical matrices discovered with the automated model findingprograms Mace [15] and MaGIC [25].

This paper posits that ethical leadership increases important organizational and individual outcomes by reducing politics in the workplace. Specifically, we propose that perceptions of organizational politics serve as a mechanism through which ethical leadership affects outcomes. We further argue that the modeled relationships are moderated by political skill. By means of data from 136 matched pairs of supervisors and subordinates employed by a state agency in the southern US, we found support for our predictions. Specifically, we found that perceptions of (...) organizational politics fully mediated the relationship between perceptions of ethical leadership and helping and promotability ratings. In addition, political skill was found to moderate the direct and indirect effects. (shrink)

Behrendt & Young (B&Y) suggest that hallucinations occur as a result of decoupling of neuronal populations from sensory control. I propose that such a decoupling is in fact a constant feature of brain activity, even under nonpathological conditions. This position is justified by evidence from recent neurophysiological recording studies. I suggest that hallucinations arise because of a breakdown in segregation of internally and externally generated activity in a neuronal population.