Psychophysical and neurophysiological studies have revealed that the visual system is sensitive to both "first-order" motion, in which moving features are defined by luminance cues, and "second-order" motion, in which motion is defined by nonluminance cues, such as contrast or flicker. Here we show psychophysically that common types of second-order stimuli provide potent cues to depth order. Al...

We present a practical first-order theory of a higher-order ⇡-calculus which is both sound and complete with respect to a standard semantic equivalence. The theory is a product of combining and simplifying two of the most prominent theories for HO⇡ of Sangiorgi et al. and Je↵rey and Rathke [10, 21], and a novel approach to scope extrusion. In this way we obtain an elementary labelled transition...

We introduce a refutation graph calculus for classical first-order predicate logic, which is an extension of previous ones for binary relations. One reduces logical consequence to establishing that a constructed graph has empty extension, i. e. it represents ⊥. Our calculus establishes that a graph has empty extension by converting it to a normal form, which is expanded to other graphs until we...

We will calculate completely the Grothendieck rings, in the sense of first order logic, of o-minimal expansions of ordered abelian groups by introducing the notion of the bounded Euler characteristic.

_______________________________________ 237 Introduction _______________________________________ 237 Methods and procedures-------.------.---------238 Acknowledgements. __--___-_-___-_____--________ 239 Geology-__________________________________ 239 Characteristics of the nodules_______________________ 240 Preservation of the fossils-_-__-_-____________________ 241 Age of the fauna_--__-__-__--...

Two new species of mites of the genus Tarsonemus Can. & Fanz., 1876: T. fraxini n. sp. and T. bistridentati n. sp. are described and illustrated based on material from instars associated with bark beetles in Ukraine. The systematic position of new species and their host relationships are briefly discussed.

In this paper we study the partially ordered set of the involutions of the symmetric group Sn with the order induced by the Bruhat order of Sn . We prove that this is a graded poset, with rank function given by the average of the number of inversions and the number of excedances, and that it is lexicographically shellable, hence Cohen-Macaulay, and Eulerian.

An abstraction mapping over clausal form theories in first-order predicate calculus is presented that involves the renaming of predicate symbols. This renaming is not 1-1, in the sense that several predicate symbols Ri,.. . , Rn from the original theory are all replaced by a single symbol R in the abstract theory. In order to preserve consistency, however, the clauses that distinguish the Rj's ...

Nowadays planning systems are usually based on partially order sets of actions as these sets specify necessary ordering constraints but do not commit otherwise. While computing these sets one usually maintains lists of links in order to detect potential threats. As shown in this paper these maintenance operations are unneccessary if the preconditions as well as eeects of actions are modelled as...

In this paper, at rst we describe a graph representing all the weak-order extensions of a partially ordered set and an algorithm generating them. Then we present a graph representing all of the minimal weak-order extensions of a partially ordered set, and implying a generation algorithm. Finally, we prove that the number of weak-order extensions of a partially ordered set is a comparability inv...