In his well-known paper \How computer should think" ((Be77b]) Belnap argues that four valued semantics is a very suitable setting for computerized reasoning. In this paper we vindicate this thesis by showing that the logical role that the four-valued structure has among Ginsberg's well-known bilattices is similar to the role that the two-valued algebra has among Boolean algebras. Speciically, w...

Axiomatic bases of admissible rules are obtained for fragments of the substructural logic R-mingle. In particular, it is shown that a “modus-ponens-like” rule introduced by Arnon Avron forms a basis for the admissible rules of its implication and implication-fusion fragments, while a basis for the admissible rules of the full multiplicative fragment requires an additional countably infinite set...

The main concern of this article is to study Ulam stability of the set of ε-approximate minima of a proper lower semicontinuous convex function bounded below on a real normed space X, when the objective function is subjected to small perturbations (in the sense of Attouch & Wets). More precisely, we characterize the class all proper lower semicontinuous convex functions bounded below such that ...

Logical systems with classical negation and means for sentential or propositional self-reference involve, in some way, paradoxical statements such as the liar. However, the paradox disappears if one replaces classical by an appropriate non-classical negation such as a paraconsistent one (no paradox arises if the liar is both true and false). We consider a non-Fregean logic which is a revised an...

We study the multi-dimensional re ection map on the spaces D([0; T ];Rk ) and D([0;1);Rk ) of right-continuous Rk -valued functions on [0; T ] or [0;1) with left limits, endowed with variants of the Skorohod(1956) M1 topology. The re ection map was used with the continuous mapping theorem by Harrison and Reiman (1981) and Reiman (1984) to establish heavy-tra c limit theorems with re ected Brown...

Abstract We study the question for which Tychonoff spaces X and locally convex E space of continuous ‐valued functions on contains a complemented copy , both endowed with pointwise topology. provide positive answer vast class spaces, extending classical theorems Cembranos, Freniche, Domański Drewnowski, proved case Banach Fréchet . Also, given infinite Y we show that if only any such subspace.

We look at extensions (i.e., stronger logics in the same language) of the Belnap-Dunn four-valued logic. We prove the existence of a countable chain of logics that extend the Belnap-Dunn and do not coincide with any of the known extensions (Kleene’s logics, Priest’s logic of paradox). We characterize the reduced algebraic models of these new logics and prove a completeness result for the first ...

In this paper, we first present new existence theorems of cone-supremum/infimum for directed convex and/or free disposal subsets in their closure. Then, we provide various conditions through which this kind of subsets admits a cone-maximum/minimum point, the so-called strongly maximal/minimal or ideal efficient points with respect to a cone. Next, we present a unifying result on the existence o...

This paper investigates the approximation of set-valued functions with compact images (not necessarily convex), by adaptations of the Schoenberg spline operators and the Bernstein polynomial operators. When replacing the sum between numbers in these operators, by the Minkowski sum between sets, the resulting operators approximate only set valued functions with compact-convex images [10]. To obt...