This paper presents a definition of universal logic in a strictly settheoretic environment and compares logical and topological properties in this abstract environment. From these properties, we verify the etymology of the ...

Tarski presented his definition of consequence operator to explain the most important notions which any logical consequence concept must contemplate. A Tarski space is a pair constituted by a nonempty set and a consequence ...

The logic TK was introduced as a propositional logic extending the classical propositional calculus with a new unary operator which interprets some conceptions of Tarski’s consequence operator. TK-algebras were introduced ...