245 found
Order:
  1.  25
    Logical Dynamics of Information and Interaction.Johan van Benthem - 2011 - Cambridge University Press.
    This book develops a view of logic as a theory of information-driven agency and intelligent interaction between many agents - with conversation, argumentation and games as guiding examples. It provides one uniform account of dynamic logics for acts of inference, observation, questions and communication, that can handle both update of knowledge and revision of beliefs. It then extends the dynamic style of analysis to include changing preferences and goals, temporal processes, group action and strategic interaction in games. Throughout, the book (...)
    Direct download  
     
    Export citation  
     
    Bookmark   105 citations  
  2.  27
    Essays in Logical Semantics.J. F. A. K. van Benthem - 1986 - Springer.
    Recent developments in the semantics of natural language seem to lead to a genuine synthesis of ideas from linguistics and logic, producing novel concepts and questions of interest to both parent disciplines. This book is a collection of essays on such new topics, which have arisen over the past few years. Taking a broad view, developments in formal semantics over the past decade can be seen as follows. At the beginning stands Montague's pioneering work, showing how a rigorous semantics can (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   106 citations  
  3.  38
    Logic in Games.Johan Van Benthem - 2014 - MIT Press.
    A comprehensive examination of the interfaces of logic, computer science, and game theory, drawing on twenty years of research on logic and games.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   42 citations  
  4. Dynamic Logic for Belief Revision.Johan van Benthem - 2007 - Journal of Applied Non-Classical Logics 17 (2):129-155.
    We show how belief revision can be treated systematically in the format of dynamicepistemic logic, when operators of conditional belief are added. The core engine consists of definable update rules for changing plausibility relations between worlds, which have been proposed independently in the dynamic-epistemic literature on preference change. Our analysis yields two new types of modal result. First, we obtain complete logics for concrete mechanisms of belief revision, based on compositional reduction axioms. Next, we show how various abstract postulates for (...)
    Direct download (5 more)  
     
    Export citation  
     
    Bookmark   149 citations  
  5.  9
    Modal Logic for Open Minds -.Johan van Benthem - 2010 - Stanford, CA, USA: Center for the Study of Language and Inf.
    In _Modal Logic for Open Minds,_ Johan van Benthem provides an up-to-date introduction to the field of modal logic, outlining its major ideas and exploring the numerous ways in which various academic fields have adopted it. Van Benthem begins with the basic theories of modal logic, semantics, bisimulation, and axiomatics, and also covers more advanced topics, such as expressive power and computational complexity. The book then moves to a wide range of applications, including new developments in information flow, intelligent agency, (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   38 citations  
  6. Modal Logic for Open Minds.Johan van Benthem - 2010 - Stanford, CA, USA: Center for the Study of Language and Information.
    In _Modal Logic for Open Minds,_ Johan van Benthem provides an up-to-date introduction to the field of modal logic, outlining its major ideas and exploring the numerous ways in which various academic fields have adopted it. Van Benthem begins with the basic theories of modal logic, semantics, bisimulation, and axiomatics, and also covers more advanced topics, such as expressive power and computational complexity. The book then moves to a wide range of applications, including new developments in information flow, intelligent agency, (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   36 citations  
  7.  74
    Logics of Communication and Change. van Benthem, Johan, van Eijck, Jan & Kooi, Barteld - unknown
    Current dynamic epistemic logics for analyzing effects of informational events often become cumbersome and opaque when common knowledge is added for groups of agents. Still, postconditions involving common knowledge are essential to successful multi-agent communication. We propose new systems that extend the epistemic base language with a new notion of ‘relativized common knowledge’, in such a way that the resulting full dynamic logic of information flow allows for a compositional analysis of all epistemic postconditions via perspicuous ‘reduction axioms’. We also (...)
    Direct download  
    Translate
     
     
    Export citation  
     
    Bookmark   109 citations  
  8. Dynamic Logic of Preference Upgrade.Johan van Benthem & Fenrong Liu - 2007 - Journal of Applied Non-Classical Logics 17 (2):157-182.
    Statements not only update our current knowledge, but also have other dynamic effects. In particular, suggestions or commands ?upgrade' our preferences by changing the current order among worlds. We present a complete logic of knowledge update plus preference upgrade that works with dynamic-epistemic-style reduction axioms. This system can model changing obligations, conflicting commands, or ?regret'. We then show how to derive reduction axioms from arbitrary definable relation changes. This style of analysis also has a product update version with preferences between (...)
    Direct download (5 more)  
     
    Export citation  
     
    Bookmark   80 citations  
  9.  51
    Modal Logic and Classical Logic.Johan van Benthem - 1983 - Distributed in the U.S.A. By Humanities Press.
  10.  90
    Handbook of Modal Logic.Patrick Blackburn, Johan van Benthem & Frank Wolter (eds.) - 2006 - Elsevier.
    The Handbook of Modal Logic contains 20 articles, which collectively introduce contemporary modal logic, survey current research, and indicate the way in which the field is developing. The articles survey the field from a wide variety of perspectives: the underling theory is explored in depth, modern computational approaches are treated, and six major applications areas of modal logic (in Mathematics, Computer Science, Artificial Intelligence, Linguistics, Game Theory, and Philosophy) are surveyed. The book contains both well-written expository articles, suitable for beginners (...)
    Direct download  
     
    Export citation  
     
    Bookmark   39 citations  
  11.  98
    Games in Dynamic-Epistemic Logic.Johan van Benthem - unknown
    We discuss games of both perfect and imperfect information at two levels of structural detail: players’ local actions, and their global powers for determining outcomes of the game. We propose matching logical languages for both. In particular, at the ‘action level’, imperfect information games naturally model a combined ‘dynamic-epistemic language’ – and we find correspondences between special axioms and particular modes of playing games with their information dynamics. At the ‘outcome level’, we present suitable notions of game equivalence, plus some (...)
    Direct download  
    Translate
     
     
    Export citation  
     
    Bookmark   54 citations  
  12.  27
    Exploring Logical Dynamics.Johan van Benthem - 2001 - Studia Logica 67 (1):111-114.
  13. 'One is a Lonely Number': On the Logic of Communication.Johan van Benthem - unknown
    Logic is not just about single-agent notions like reasoning, or zero-agent notions like truth, but also about communication between two or more people. What we tell and ask each other can be just as 'logical' as what we infer in Olympic solitude. We show how such interactive phenomena can be studied systematically by merging epistemic and dynamic logic.
    Translate
     
     
    Export citation  
     
    Bookmark   57 citations  
  14. Modal Languages and Bounded Fragments of Predicate Logic.Hajnal Andréka, István Németi & Johan van Benthem - 1998 - Journal of Philosophical Logic 27 (3):217 - 274.
    What precisely are fragments of classical first-order logic showing “modal” behaviour? Perhaps the most influential answer is that of Gabbay 1981, which identifies them with so-called “finite-variable fragments”, using only some fixed finite number of variables (free or bound). This view-point has been endorsed by many authors (cf. van Benthem 1991). We will investigate these fragments, and find that, illuminating and interesting though they are, they lack the required nice behaviour in our sense. (Several new negative results support this claim.) (...)
    Direct download (8 more)  
     
    Export citation  
     
    Bookmark   75 citations  
  15.  65
    Merging Frameworks for Interaction.Johan van Benthem, Jelle Gerbrandy, Tomohiro Hoshi & Eric Pacuit - 2009 - Journal of Philosophical Logic 38 (5):491-526.
    A variety of logical frameworks have been developed to study rational agents interacting over time. This paper takes a closer look at one particular interface, between two systems that both address the dynamics of knowledge and information flow. The first is Epistemic Temporal Logic (ETL) which uses linear or branching time models with added epistemic structure induced by agents’ different capabilities for observing events. The second framework is Dynamic Epistemic Logic (DEL) that describes interactive processes in terms of epistemic event (...)
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   62 citations  
  16.  80
    Dynamic Logics of Evidence-Based Beliefs.Johan van Benthem & Eric Pacuit - 2011 - Studia Logica 99 (1-3):61-92.
    This paper adds evidence structure to standard models of belief, in the form of families of sets of worlds. We show how these more fine-grained models support natural actions of “evidence management”, ranging from update with external new information to internal rearrangement. We show how this perspective leads to new richer languages for existing neighborhood semantics for modal logic. Our main results are relative completeness theorems for the resulting dynamic logic of evidence.
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   39 citations  
  17.  15
    Language in Action.Johan Van Benthem - 1991 - Journal of Philosophical Logic 20 (3):225-263.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   84 citations  
  18.  1
    Language in Action: Categories, Lambdas and Dynamic Logic.Johan van Benthem - 1995 - MIT Press.
    Language in Action demonstrates the viability of mathematical research into the foundations of categorial grammar, a topic at the border between logic and linguistics. Since its initial publication it has become the classic work in the foundations of categorial grammar. A new introduction to this paperback edition updates the open research problems and records relevant results through pointers to the literature. Van Benthem presents the categorial processing of syntax and semantics as a central component in a more general dynamic logic (...)
    Direct download  
     
    Export citation  
     
    Bookmark   28 citations  
  19. Rational Dynamics and Epistemic Logic in Games.Johan van Benthem - unknown
    Game-theoretic solution concepts describe sets of strategy profiles that are optimal for all players in some plausible sense. Such sets are often found by recursive algorithms like iterated removal of strictly dominated strategies in strategic games, or backward induction in extensive games. Standard logical analyses of solution sets use assumptions about players in fixed epistemic models for a given game, such as mutual knowledge of rationality. In this paper, we propose a different perspective, analyzing solution algorithms as processes of learning (...)
    Direct download  
    Translate
     
     
    Export citation  
     
    Bookmark   28 citations  
  20.  50
    Toward a Dynamic Logic of Questions.Johan van Benthem & Ştefan Minică - 2012 - Journal of Philosophical Logic 41 (4):633-669.
    Questions are triggers for explicit events of ‘issue management’. We give a complete logic in dynamic-epistemic style for events of raising, refining, and resolving an issue, all in the presence of information flow through observation or communication. We explore extensions of the framework to multi-agent scenarios and long-term temporal protocols. We sketch a comparison with some alternative accounts.
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   28 citations  
  21.  84
    Logic and Reasoning: Do the Facts Matter?Johan van Benthem - 2008 - Studia Logica 88 (1):67-84.
    Modern logic is undergoing a cognitive turn, side-stepping Frege’s ‘antipsychologism’. Collaborations between logicians and colleagues in more empirical fields are growing, especially in research on reasoning and information update by intelligent agents. We place this border-crossing research in the context of long-standing contacts between logic and empirical facts, since pure normativity has never been a plausible stance. We also discuss what the fall of Frege’s Wall means for a new agenda of logic as a theory of rational agency, and what (...)
    Direct download (7 more)  
     
    Export citation  
     
    Bookmark   35 citations  
  22. Essays in Logical Semantics.Johan van Benthem - 1988 - Studia Logica 47 (2):172-173.
     
    Export citation  
     
    Bookmark   53 citations  
  23.  63
    Questions About Quantifiers.Johan van Benthem - 1984 - Journal of Symbolic Logic 49 (2):443-466.
  24. Preference Logic, Conditionals and Solution Concepts in Games.Johan van Benthem - unknown
    Preference is a basic notion in human behaviour, underlying such varied phenomena as individual rationality in the philosophy of action and game theory, obligations in deontic logic (we should aim for the best of all possible worlds), or collective decisions in social choice theory. Also, in a more abstract sense, preference orderings are used in conditional logic or non-monotonic reasoning as a way of arranging worlds into more or less plausible ones. The field of preference logic (cf. Hansson [10]) studies (...)
    Translate
     
     
    Export citation  
     
    Bookmark   25 citations  
  25. Dynamic Update with Probabilities.Johan van Benthem, Jelle Gerbrandy & Barteld Kooi - 2009 - Studia Logica 93 (1):67 - 96.
    Current dynamic-epistemic logics model different types of information change in multi-agent scenarios. We generalize these logics to a probabilistic setting, obtaining a calculus for multi-agent update with three natural slots: prior probability on states, occurrence probabilities in the relevant process taking place, and observation probabilities of events. To match this update mechanism, we present a complete dynamic logic of information change with a probabilistic character. The completeness proof follows a compositional methodology that applies to a much larger class of dynamic-probabilistic (...)
    Direct download (12 more)  
     
    Export citation  
     
    Bookmark   22 citations  
  26.  27
    What One May Come to Know.J. van Benthem - 2004 - Analysis 64 (2):95-105.
    No categories
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   45 citations  
  27. Handbook of Logic and Language.J. F. A. K. Van Benthem, Johan van Benthem & Alice G. B. Ter Meulen (eds.) - 1997 - MIT Press.
    This Handbook documents the main trends in current research between logic and language, including its broader influence in computer science, linguistic theory and cognitive science. The history of the combined study of Logic and Linguistics goes back a long way, at least to the work of the scholastic philosophers in the Middle Ages. At the beginning of this century, the subject was revitalized through the pioneering efforts of Gottlob Frege, Bertrand Russell, and Polish philosophical logicians such as Kazimierz Ajdukiewicz. Around (...)
    Direct download  
     
    Export citation  
     
    Bookmark   21 citations  
  28. Epistemic Logic and Epistemology: The State of Their Affairs.Johan van Benthem - 2006 - Philosophical Studies 128 (1):49 - 76.
    Epistemology and epistemic logic At first sight, the modern agenda of epistemology has little to do with logic. Topics include different definitions of knowledge, its basic formal properties, debates between externalist and internalist positions, and above all: perennial encounters with sceptics lurking behind every street corner, especially in the US. The entry 'Epistemology' in the Routledge Encyclopedia of Philosophy (Klein 1993) and the anthology (Kim and Sosa 2000) give an up-to-date impression of the field. Now, epistemic logic started as a (...)
    Direct download (5 more)  
     
    Export citation  
     
    Bookmark   24 citations  
  29.  22
    Instantial Neighbourhood Logic.Johan van Benthem, Nick Bezhanishvili, Sebastian Enqvist & Junhua Yu - 2017 - Review of Symbolic Logic 10 (1):116-144.
    This paper explores a new language of neighbourhood structures where existential information can be given about what kind of worlds occur in a neighbourhood of a current world. The resulting system of ‘instantial neighbourhood logic’ INL has a nontrivial mix of features from relational semantics and from neighbourhood semantics. We explore some basic model-theoretic behavior, including a matching notion of bisimulation, and give a complete axiom system for which we prove completeness by a new normal form technique. In addition, we (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   9 citations  
  30.  97
    The Dynamics of Awareness.Fernando R. Velázquez-Quesada & Johan van Benthem - 2010 - Synthese 177 (S1):5 - 27.
    Classical epistemic logic describes implicit knowledge of agents about facts and knowledge of other agents based on semantic information. The latter is produced by acts of observation or communication that are described well by dynamic epistemic logics. What these logics do not describe, however, is how significant information is also produced by acts of inference— and key axioms of the system merely postulate "deductive closure". In this paper, we take the view that all information is produced by acts, and hence (...)
    Direct download (8 more)  
     
    Export citation  
     
    Bookmark   17 citations  
  31.  85
    The Logic of Time: A Model-Theoretic Investigation Into the Varieties of Temporal Ontology and Temporal Discourse.Johan van Benthem - 1982 - Dordrecht, Netherland: Kluwer Academic Publishers.
    The subject of Time has a wide intellectual appeal across different dis ciplines. This has shown in the variety of reactions received from readers of the first edition of the present Book. Many have reacted to issues raised in its philosophical discussions, while some have even solved a number of the open technical questions raised in the logical elaboration of the latter. These results will be recorded below, at a more convenient place. In the seven years after the first publication, (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   18 citations  
  32. What One May Come to Know.van Benthem Johan - 2004 - Analysis 64 (2):95–105.
    The general verificationist thesis says that What is true can be known or formally: φ → ◊Kφ VT Fitch's argument trivializes this principle. It uses a weak modal epistemic logic to show that VT collapses truth and knowledge, by taking a clever substitution instance for φ: P ∧ ¬KP → ◊ K(P ∧ ¬KP) Then we have the following chain of three conditionals (a) ◊ K(P ∧ ¬KP) → ◊ (KP ∧ K¬KP) in the minimal modal logic for the knowledge (...)
    Direct download (6 more)  
     
    Export citation  
     
    Bookmark   24 citations  
  33. The Stories of Logic and Information.Johan van Benthem, Maricarmen Martinez, David Israel & John Perry - unknown
    Information is a notion of wide use and great intuitive appeal, and hence, not surprisingly, different formal paradigms claim part of it, from Shannon channel theory to Kolmogorov complexity. Information is also a widely used term in logic, but a similar diversity repeats itself: there are several competing logical accounts of this notion, ranging from semantic to syntactic. In this chapter, we will discuss three major logical accounts of information.
    Translate
     
     
    Export citation  
     
    Bookmark   16 citations  
  34.  69
    Modal Logic: A Semantic Perspective.Patrick Blackburn & Johan van Benthem - 1988 - Ethics 98:501-517.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 BASIC MODAL LOGIC . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   32 citations  
  35.  1
    Handbook of Spatial Logics.Marco Aiello, Ian Pratt-Hartmann & Johan van Benthem (eds.) - 2007 - Springer Verlag.
    A spatial logic is a formal language interpreted over any class of structures featuring geometrical entities and relations, broadly construed. In the past decade, spatial logics have attracted much attention in response to developments in such diverse fields as Artificial Intelligence, Database Theory, Physics, and Philosophy. The aim of this handbook is to create, for the first time, a systematic account of the field of spatial logic. The book comprises a general introduction, followed by fourteen chapters by invited authors. Each (...)
    Direct download  
     
    Export citation  
     
    Bookmark   13 citations  
  36. Dynamics.Reinhard Muskens, Johan Van Benthem & Albert Visser - 1997 - In Johan Van Benthem & Alice Ter Meulen (eds.), Handbook of Logic and Language. Amsterdam: Elsevier. pp. 587-648.
  37.  14
    Polyadic Quantifiers.Johan Van Benthem - 1989 - Linguistics and Philosophy 12 (4):437-464.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   36 citations  
  38.  85
    The Logic of Empirical Theories Revisited.Johan van Benthem - 2012 - Synthese 186 (3):775-792.
    Logic and philosophy of science share a long history, though contacts have gone through ups and downs. This paper is a brief survey of some major themes in logical studies of empirical theories, including links to computer science and current studies of rational agency. The survey has no new results: we just try to make some things into common knowledge.
    Direct download (10 more)  
     
    Export citation  
     
    Bookmark   12 citations  
  39.  27
    Logical Constants Across Varying Types.Johan van Benthem - 1989 - Notre Dame Journal of Formal Logic 30 (3):315-342.
  40.  85
    Multimo Dal Logics of Products of Topologies.Johan van Benthem, Guram Bezhanishvili, Balder ten Cate & Darko Sarenac - 2006 - Studia Logica 84 (3):369-392.
    We introduce the horizontal and vertical topologies on the product of topological spaces, and study their relationship with the standard product topology. We show that the modal logic of products of topological spaces with horizontal and vertical topologies is the fusion ${\bf S4}\oplus {\bf S4}$ . We axiomatize the modal logic of products of spaces with horizontal, vertical, and standard product topologies. We prove that both of these logics are complete for the product of rational numbers ${\Bbb Q}\times {\Bbb Q}$ (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   19 citations  
  41. Categorial Grammar.Wojciech Buszkowski, Witold Marciszewski & Johan van Benthem - 1991 - Studia Logica 50 (1):171-172.
     
    Export citation  
     
    Bookmark   28 citations  
  42.  88
    Extensive Games as Process Models.Johan van Benthem - 2002 - Journal of Logic, Language and Information 11 (3):289-313.
    We analyze extensive games as interactive process models, using modallanguages plus matching notions of bisimulation as varieties of gameequivalences. Our technical results show how to fit existing modalnotions into this new setting.
    Direct download (5 more)  
     
    Export citation  
     
    Bookmark   26 citations  
  43.  48
    Logical Dynamics Meets Logical Pluralism?Johan van Benthem - 2008 - Australasian Journal of Logic 6:182-209.
    Where is logic heading today? There is a general feeling that the discipline is broadening its scope and agenda beyond classical foundational issues, and maybe even a concern that, like Stephen Leacock’s famous horseman, it is ‘riding off madly in all directions’. So, what is the resultant vector? There seem to be two broad answers in circulation today. One is logical pluralism, locating the new scope of logic in charting a wide variety of reasoning styles, often marked by non-classical structural (...)
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   16 citations  
  44. Open Problems in Logic and Games.Johan van Benthem - unknown
    Dov Gabbay is a prolific logician just by himself. But beyond that, he is quite good at making other people investigate the many further things he cares about. As a result, King's College London has become a powerful attractor in our field worldwide. Thus, it is a great pleasure to be an organizer for one of its flagship events: the Augustus de Morgan Workshop of 2005. Benedikt Loewe and I proposed the topic of 'interactive logic' for this occasion, with an (...)
    Translate
     
     
    Export citation  
     
    Bookmark   11 citations  
  45. Merging Observation and Access in Dynamic Logic.Johan van Benthem - unknown
    Rational agents base their actions on information from observation, inference, introspection, or other sources. But this information comes in different kinds, and it is usually handled by different logical mechanisms. We discuss how to integrate external ‘updating information’ and internal ‘elucidating information’ into one system of dynamic epistemic logic, by distinguishing two basic informational actions: ‘bare seeing’ versus ‘conscious realization’.
    Translate
     
     
    Export citation  
     
    Bookmark   14 citations  
  46.  3
    Handbook of Logic and Language.J. F. A. K. Van Benthem & Alice G. B. Ter Meulen (eds.) - 1997 - MIT Press.
    This Handbook documents the main trends in current research between logic and language, including its broader influence in computer science, linguistic theory and cognitive science. The history of the combined study of Logic and Linguistics goes back a long way, at least to the work of the scholastic philosophers in the Middle Ages. At the beginning of this century, the subject was revitalized through the pioneering efforts of Gottlob Frege, Bertrand Russell, and Polish philosophical logicians such as Kazimierz Ajdukiewicz. Around (...)
    Direct download  
     
    Export citation  
     
    Bookmark   13 citations  
  47.  67
    The Geometry of Knowledge.Johan van Benthem & Darko Sarenac - unknown
    The most widely used attractive logical account of knowledge uses standard epistemic models, i.e., graphs whose edges are indistinguishability relations for agents. In this paper, we discuss more general topological models for a multi-agent epistemic language, whose main uses so far have been in reasoning about space. We show that this more geometrical perspective affords greater powers of distinction in the study of common knowledge, defining new collective agents, and merging information for groups of agents.
    Direct download  
    Translate
     
     
    Export citation  
     
    Bookmark   12 citations  
  48.  4
    Priority Structures in Deontic Logic.Johan van Benthem, Davide Grossi & Fenrong Liu - 2014 - Theoria 80 (2):116-152.
    No categories
    Direct download  
     
    Export citation  
     
    Bookmark   12 citations  
  49.  37
    Evidence and Plausibility in Neighborhood Structures.Johan van Benthem, David Fernández-Duque & Eric Pacuit - 2014 - Annals of Pure and Applied Logic 165 (1):106-133.
    The intuitive notion of evidence has both semantic and syntactic features. In this paper, we develop an evidence logic for epistemic agents faced with possibly contradictory evidence from different sources. The logic is based on a neighborhood semantics, where a neighborhood N indicates that the agent has reason to believe that the true state of the world lies in N. Further notions of relative plausibility between worlds and beliefs based on the latter ordering are then defined in terms of this (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   9 citations  
  50.  83
    Determiners and Logic.Johan van Benthem - 1983 - Linguistics and Philosophy 6 (4):447-478.
1 — 50 / 245