• Propositions, Propositional Attitudes and Belief Revision
    In Marcus Kracht, Maarten de Rijke, Heinrich Wansing & Michael Zakharyaschev (eds.), Advances in Modal Logic, Csli Publications. pp. 399-418. 1998.
  •  35
    Indian Institute of Technology, Kanpur January 14–26, 2008
    with Ramon Jansana, Mai Gehrke, Alessandra Palmigiano, Mihir K. Chakraborty, Didier Dubois, Eric Pacuit, and Prakash Panangaden
    Bulletin of Symbolic Logic 14 (4). 2008.
  •  48
    We propose a new relevance sensitive model for representing and revising belief structures, which relies on a notion of partial language splitting and tolerates some amount of inconsistency while retaining classical logic. The model preserves an agent's ability to answer queries in a coherent way using Belnap's four-valued logic. Axioms analogous to the AGM axioms hold for this new model. The distinction between implicit and explicit beliefs is represented and psychologically plausible, computat…Read more
  •  36
    Finite information logic
    Annals of Pure and Applied Logic 134 (1): 83-93. 2005.
    We introduce a generalization of Independence Friendly logic in which Eloise is restricted to a finite amount of information about Abelard’s moves. This logic is shown to be equivalent to a sublogic of first-order logic, to have the finite model property, and to be decidable. Moreover, it gives an exponential compression relative to logic
  •  102
    The Logic of Knowledge Based Obligation
    with Eric Pacuit and Eva Cogan
    Synthese 149 (2): 311-341. 2006.
    Deontic Logic goes back to Ernst Mally’s 1926 work, Grundgesetze des Sollens: Elemente der Logik des Willens [Mally. E.: 1926, Grundgesetze des Sollens: Elemente der Logik des Willens, Leuschner & Lubensky, Graz], where he presented axioms for the notion ‘p ought to be the case’. Some difficulties were found in Mally’s axioms, and the field has much developed. Logic of Knowledge goes back to Hintikka’s work Knowledge and Belief [Hintikka, J.: 1962, Knowledge and Belief: An Introduction to the Lo…Read more
  •  63
    2000-2001 Spring Meeting of the Association for Symbolic Logic
    with Michael Detlefsen, Erich Reck, Colin McLarty, Larry Moss, Scott Weinstein, Gabriel Uzquiano, Grigori Mints, and Richard Zach
    Bulletin of Symbolic Logic 7 (3): 413-419. 2001.
  •  108
    Relevance Sensitive Non-Monotonic Inference on Belief Sequences
    Journal of Applied Non-Classical Logics 11 (1): 131-150. 2001.
    We present a method for relevance sensitive non-monotonic inference from belief sequences which incorporates insights pertaining to prioritized inference and relevance sensitive, inconsistency tolerant belief revision. Our model uses a finite, logically open sequence of propositional formulas as a representation for beliefs and defines a notion of inference from maxiconsistent subsets of formulas guided by two orderings: a temporal sequencing and an ordering based on relevance relations between …Read more
  •  20
    Approximate belief revision
    with S. Chopra and R. Wassermann
    Logic Journal of the IGPL 9 (6): 755-768. 2001.
    The standard theory for belief revision provides an elegant and powerful framework for reasoning about how a rational agent should change its beliefs when confronted with new information. However, the agents considered are extremely idealized. Some recent models attempt to tackle the problem of plausible belief revision by adding structure to the belief bases and using nonstandard inference operations. One of the key ideas is that not all of an agent's beliefs are relevant for an operation of be…Read more
  •  20
    Logic, co-ordination and the envelope of our beliefs
    Logic Journal of the IGPL 31 (6): 1069-1077. 2023.
    Each of us has a story which we can think of as a set of beliefs, hopefully consistent. We make our decisions in view of our beliefs which may be probabilistic, in the general case, but simple yes or no as in this paper. Our beliefs are our envelope just as the shell of a tortoise is its envelope. Decision theory—or single agent game theory tells us when to make the best choice in a game of us against nature. But nature has no desire to further or frustrate our efforts. Nature is mysterious but …Read more
  •  13
    Proof, Computation and Agency: Logic at the Crossroads (edited book)
    with Johan van Benthem and Amitabha Gupta
    Springer. 2011.
    Proof, Computation and Agency: Logic at the Crossroads provides an overview of modern logic and its relationship with other disciplines. As a highlight, several articles pursue an inspiring paradigm called 'social software', which studies patterns of social interaction using techniques from logic and computer science. The book also demonstrates how logic can join forces with game theory and social choice theory. A second main line is the logic-language-cognition connection, where the articles co…Read more
  •  31
    Knowledge, behavior, and rationality: rationalizability in epistemic games
    Archive for Mathematical Logic 60 (5): 599-623. 2021.
    In strategic situations, agents base actions on knowledge and beliefs. This includes knowledge about others’ strategies and preferences over strategy profiles, but also about other external factors. Bernheim and Pearce in 1984 independently defined the game theoretic solution concept of rationalizability, which is built on the premise that rational agents will only take actions that are the best response to some situation that they consider possible. This accounts for other agents’ rationality a…Read more
  •  62
    On knowledge and obligation
    with Can Başķent and Loes Olde Loohuis
    Episteme 9 (2): 171-188. 2012.
    This article provides a brief overview of several formal frameworks concerning the relation between knowledge on the one hand, and obligation on the other. We discuss the paradox of the knower, knowledge based obligation, knowingly doing, deontic dynamic epistemology, descriptive obligations, and responsibilities as dynamic epistemology.
  • Propositions, Propositional Attitudes and Belief Revision
    In Marcus Kracht, Maarten de Rijke, Heinrich Wansing & Michael Zakharyaschev (eds.), Advances in Modal Logic, Csli Publications. pp. 399-418. 1998.
  •  6
  • The Complete Bibliography of Rohit Parikh
    In Ramaswamy Ramanujam, Lawrence Moss & Can Başkent (eds.), Rohit Parikh on Logic, Language and Society, Springer Verlag. 2017.
  •  82
    Logic in India—Editorial Introduction
    with R. Ramanujam and Hans van Ditmarsch
    Journal of Philosophical Logic 40 (5): 557-561. 2011.
  •  37
    Some Generalisations of the Notion of Well Ordering
    Mathematical Logic Quarterly 12 (1): 333-340. 1966.
  •  63
    Obituary: Horacio Arló-costa
    Episteme 9 (2): 89-89. 2012.
    Editorial Rohit Parikh, Jeffrey Helzner, Episteme, FirstView Article
  •  55
    Completeness of Certain Bimodal Logics for Subset Spaces
    with M. Angela Weiss
    Studia Logica 71 (1): 1-30. 2002.
    Subset Spaces were introduced by L. Moss and R. Parikh in [8]. These spaces model the reasoning about knowledge of changing states.In [2] a kind of subset space called intersection space was considered and the question about the existence of a set of axioms that is complete for the logic of intersection spaces was addressed. In [9] the first author introduced the class of directed spaces and proved that any set of axioms for directed frames also characterizes intersection spaces.We give here a c…Read more
  •  147
    Conditional Probability and Defeasible Inference
    Journal of Philosophical Logic 34 (1). 2005.
    We offer a probabilistic model of rational consequence relations (Lehmann and Magidor, 1990) by appealing to the extension of the classical Ramsey-Adams test proposed by Vann McGee in (McGee, 1994). Previous and influential models of nonmonotonic consequence relations have been produced in terms of the dynamics of expectations (Gärdenfors and Makinson, 1994; Gärdenfors, 1993).'Expectation' is a term of art in these models, which should not be confused with the notion of expected utility. The exp…Read more
  •  53
    Topological reasoning and the logic of knowledge
    with Andrew Dabrowski and Lawrence S. Moss
    Annals of Pure and Applied Logic 78 (1-3): 73-110. 1996.
    We present a bimodal logic suitable for formalizing reasoning about points and sets, and also states of the world and views about them. The most natural interpretation of the logic is in subset spaces , and we obtain complete axiomatizations for the sentences which hold in these interpretations. In addition, we axiomatize the validities of the smaller class of topological spaces in a system we call topologic . We also prove decidability for these two systems. Our results on topologic relate earl…Read more
  •  36
    Vague Predicates and Language Games
    Theoria: Revista de Teoría, Historia y Fundamentos de la Ciencia 11 (3): 97-107. 1996.
    Attempts to give a Logic or Semantics for vague predicates and to defuse the Sorites paradoxes have been largely a failure. We point out yet another problem with these predicates which has not been remarked on before,namely that different people do and must use these predicates in individually different ways. Thus even if there were a semantics for vague predicates, people would not be able to share it. To explain the occurrence nonetheless of these troublesome predicates in language, we propose…Read more
  • Some Reminiscences of Kreisel
    In Piergiorgio Odifreddi (ed.), Kreiseliana: About and Around Georg Kreisel, A K Peters. pp. 89. 1996.