It is well known that the model categories of universal Horn theories are locally presentable, hence essentially algebraic [2]. In the special case of quasivarieties a direct tran...
In Zermelo-Fraenkel set theory with the axiom of choice every set has the same cardinal number as some ordinal. Von Rimscha has weakened this condition to "Every set has the s...
The axiom of multiple choice implies that metric spaces are paracompact but the reverse implication cannot be proved in set theory without the axiom of choice.
Paul E. Howard, Kyriakos Keremedis, Jean E. Rubin,...
: Each information system (or data table) leads to a hierarchy of binary relations on the object set in a natural way; these relational systems can serve as frames for the semantic...
The logic of common belief does not always reect that of individual beliefs. In particular, even when the individual belief operators satisfy the KD45 logic, the common belief ope...
The connection between similarity logic and the theory of closure operators is examined. Indeed one proves that the consequence relation defined in [14] can be obtained by composin...
We give a corrected proof of an extension of the Robinson Splitting Theorem for the d.c.e. degrees. The purpose of this short paper is to clarify and correct the main result and p...