Sumit Sourabh

Learn More
By de Vries duality, the category of compact Hausdorff spaces is dually equivalent to the category of de Vries algebras (complete Boolean algebras endowed with a proximity-like relation). We provide an alternative “modal-like” duality by introducing the concept of a Gleason space, which is a pair (X,R), where X is an extremally disconnected compact(More)
We introduce a new order-topological semantics for the positive modal mu-calculus over modal compact Hausdorff spaces, which are generalizations of descriptive frames. We define Sahlqvist sequents in this language, prove Esakia’s lemma and Sahlqvist preservation theorem for this semantics. We show that every Sahlqvist sequent has a frame correspondent in(More)
In the present paper, the algorithmic correspondence theory developed in (Conradie and Palmigiano, 2012) is extended to mu-calculi with a non-classical base. We focus in particular on the language of bi-intuitionistic modal mu-calculus. We enhance the algorithm ALBA introduced in (Conradie and Palmigiano, 2012) so as to guarantee its success on the class of(More)
The theory of canonical extensions typically considers extensions of maps A ! B to maps A ! B . In the present paper, the theory of canonical extensions of maps A ! B to maps A ! B is developed, and is applied to obtain a new canonicity proof for those inequalities in the language of Distributive Modal Logic (DML) on which the algorithm ALBA [9] is(More)
This paper provides a bridge in the gap between the model-theoretic and the algebraic side of modal correspondence theory. We give a new, algebraic proof of the classical Sahlqvist correspondence theorem, as well as a new, algebraic proof of the analogous result for the atomic inductive formulas, which form a proper extension of the Sahlqvist class.
Sahlqvist-style correspondence results remain a perennial theme and an active topic of research within modal logic. Recently, there has been interest in extending the classical results in this area to the modal mu-calculus [7]. For instance, in [8] van Benthem, Bezhanishvili and Hodkinson define a class of Sahlqvist formulas for the modal mu-calculus, all(More)
Introduction. This paper reports the development of a simple tool, NEGEXT, written in the platform-independent Java language. NEGEXT has been constructed to aid real people doing actual negotiations, when the ways to negotiate are simply too many to be computed by a normal human mind. This toolkit will also help in planning one’s strategic moves in(More)