4 papers
On a Second-Order Version of Russellian Theory of Definite Descriptions
Yaroslav Petrukhin
Definite descriptions are first-order expressions that denote unique objects. In this paper, we propose a second-order counterpart, designed to refer to unique relations between ob…
A Binary Quantifier for Definite Descriptions in Nelsonian Free Logic
Yaroslav Petrukhin
The method Kürbis used to formalise definite descriptions with a binary quantifier I, such that I indicates `the F is G', is examined and improved upon in this work. Kürb…
Bisequent Calculi for Neutral Free Logic with Definite Descriptions
Andrzej Indrzejczak, Yaroslav Petrukhin
We present a bisequent calculus (BSC) for the minimal theory of definite descriptions (DD) in the setting of neutral free logic, where formulae with non-denoting terms have no trut…
Uniform Cut-free Bisequent Calculi for Three-valued Logics
Andrzej Indrzejczak, Yaroslav Petrukhin
We present a uniform characterisation of three-valued logics by means of the bisequent calculus (BSC). It is a generalised form of a sequent calculus (SC) where rules operate on th…