
	Where results make sense

Topic: Modal logic S5

Related Topics

logical fallacies

mathematical logic

logic gate

logical positivism

symbolic logic

intuitionistic logic

fuzzy logic

Combinatory logic

modal logic

logical argument

Logical disjunction

first order logic

In the News (Sat 26 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Modal logic - Wikipedia, the free encyclopedia
		Logics for handling a number of other ideas, such as eventually, formerly, can, could, might, may, must are by extension also called modal logics, since it turns out that these can be treated in similar ways.
		Logical possibility is a form of alethic possibility; (4) makes a claim about whether it is possible for a mathematical truth to have been false, but (3) only makes a claim about whether it is possible that the mathematical claim turns out false, for all Jones knows, and so again Jones does not contradict himself.
		Significantly, modal logics can be developed to accommodate most of these idioms; it is the fact of their common logical structure (the use of "intensional" or non-truth-functional sentential operators) that make them all varieties of the same thing.
	en.wikipedia.org /wiki/Modal_logic (2613 words)

	Modal Logic
		Modal logic is, strictly speaking, the study of the deductive behavior of the expressions ‘it is necessary that’ and ‘it is possible that’.
		For this reason, there is no one modal logic, but rather a whole family of systems built around M. The relationship between these systems is diagrammed in Section 8, and their application to different uses of ‘necessarily’ and ‘possibly’ can be more deeply understood by studying their possible world semantics in Section 6.
		Deontic logics introduce the primitive symbol O for ‘it is obligatory that’, from which symbols P for ‘it is permitted that’ and F for ‘it is forbidden that’ are defined: PA = ~O~A and FA = O~A. The deontic analog of the modal axiom (M): OA→A is clearly not appropriate for deontic logic.
	plato.stanford.edu /entries/logic-modal (7308 words)

	Modal logic - ExampleProblems.com
		A modal logic, or (less commonly) intensional logic, is a logic that deals with sentences that are qualified by modalities such as can, could, might, may, must, possibly, necessarily, eventually, etc. Modal logics are characterized by semantic intensionality: the truth value of a complex formula cannot be determined by the truth values of its subformulae.
		Modal operators cannot be formalized by an extensional semantics: both "George W. Bush is President of the United States" and "2 + 2 = 4" are true, yet "Necessarily, George W. Bush is President of the United States" is false, while "Necessarily, 2 + 2 = 4" is true.
		The founder of formal modal logic is C.
	www.exampleproblems.com /wiki/index.php/Modal_logic (1900 words)

	Re: modal logic
		I believe that some notion of modality is unavoidable for formal ontology, and I agree what you seem to suggest, that the minimal modal logic S5 is adequate for most cases.
		I would like to underline that in many cases a modal semantics is necessary to understand an ontological axiom, but the axiom itself does not need to be expressed in modal language.
		I relied on modality and intensionality when trying to clarify the notion of "conceptualization" that appears in Tom Gruber's definition "An ontology is a specification of a conceptualization" (see http://www.ladseb.pd.cnr.it/infor/Ontology/Papers/FOIS98.pdf): a conceptualization can't be a "static" view of the world, but it rather accounts for the way we deal with changes in the world, i.e.
	suo.ieee.org /email/msg00124.html (406 words)

	Ontological argument - Wikipedia, the free encyclopedia
		A modal logic version of the argument was devised by mathematican Kurt Gödel.
		Leibniz thought that the possibility premise followed from the claim that "positive qualities" could not logically conflict with one another, and hence the notion of a being that had all the positive qualities had to be coherent.
		Paul E. Oppenheimer and Edward N. Zalta, "On the Logic of the Ontological Argument" from James Tomberlin ed., Philosophical Perspectives 5: The Philosophy of Religion (Atascadero: Ridgeview, 1991) pp.
	en.wikipedia.org /wiki/Ontological_argument (4184 words)

	DI & CoS - Modal Logic
		While we can formulate several modal logics in the sequent calculus that enjoy cut-elimination, their formalisation arises through system-by-system fine tuning to ensure that the cut-elimination holds, and the correspondence to the formulation in the Hilbert-Lewis systems becomes opaque.
		Because of this, we are able to axiomatise the modal logics in a manner directly analogous to the Hilbert-Lewis axiomatisation.
		Consequently, modal logic is seen as logic of relational structures, where logical axioms correspond to structural properties.
	alessio.guglielmi.name /res/cos/ML (973 words)

	Modal logic (Site not responding. Last check: 2007-10-11)
		Modal logic is a form of logic which deals with sentences that are qualified by modalities such as possibly, necessarily, contingently, actually, can, could, might, may, must, ought, and others.
		Modal logic is most often used for talk of the so-called alethic modalities: "it is necessarily the case that..." or "it is possibly the case that...." These (also called metaphysical modalities or subjunctive modalities) need to be distinguished from various similar-sounding claims using epistemic modalities.
		The contemporary logical analysis of modality can be traced to C.I. Lewis' "A Survey of Symbolic Logic" (1918), in which he he developed the logical systems S1-S5.
	ccc.domaindlx.com /kazenoouji/modal_logic.htm (1367 words)

	The $100 Challenge (Site not responding. Last check: 2007-10-11)
		Logic provides a rich source of challenges, to determine the relationships between different logics, and between different axiomatizations of the same logic.
		In modal logics, the lattice of relationships between the Kripke based logics up to S5 is a well known structure.
		For example, the KM4B axiomatization of the modal logic S5 is equivalent to the KM5 axiomatization.
	www.cs.miami.edu /~tptp/HHDC (512 words)

	Modal Logic (Site not responding. Last check: 2007-10-11)
		Unfortunately, all the early attempts at modal predicate calculi had unintuitive theorems (see for instance Kripke 1963a), and, moreover, all of them met with difficulties connected with the failure of Leibniz' law of identity, which we shall try to outline.
		Actually, in order to get different modal logics (and even then not all of them) one has to be a bit more subtle, and have a binary relation on the set of possible worlds--the alternativeness relation.
		It is possible to gain the expressive power of modal logic without using modal operators by constructing an ordinary truth-functional logic which describes the multiple-world semantics of modal logic directly.
	www-formal.stanford.edu /jmc/mcchay69/node22.html (1380 words)

	CiteULike: A Cut-Free Gentzen Formulation of the Modal Logic S5 (Site not responding. Last check: 2007-10-11)
		A Cut-Free Gentzen Formulation of the Modal Logic S5 Logic Journal of the IGPL, Vol.
		The goal of this paper is to introduce a new Gentzen formulation of the modal logic S5.
		In this paper we give a new sequent system for S5 which is a straightforward and technically simple extension of Gentzen's original sequent system for classical logic.
	www.citeulike.org /user/greg_restall/article/267580 (314 words)

	RE: modal logic
		I agree what you seem to > >suggest, that the minimal modal logic S5 is adequate for most cases.
		S5 is one of the strongest of all > versions of modal logic, and in an earlier note, I cited the example > to show that S4 is closer to the usual policy of database > administrators.
		> > >>S5 is the most popular, but some philosophers (notably > Nathan Salmon) > >>have argued that it is too strong, especially with regard > to the modal > >>properties of artifacts.
	grouper.ieee.org /groups/suo/email/msg00153.html (376 words)

	Barcan formula: Definition and Links by Encyclopedian.com
		The Barcan formula is used in Kripke-System-5 Kripke System 5 S5 Modal-logic Modal...Modal-logic Modal logic modal logic of the Kripke-System Kripke System Kripke System.
		The formula tells us that if everything is quantifiable in all other worlds then it would have to be necessary that everything is quantifiable in our world as well.
		The Barcan formula is used in S5[?] modal logic[?] of the Kripke System[?].
	www.encyclopedian.com /ba/Barcan-formula.html (193 words)

	Resolution Based Theorem Proving for Temporal Logics of Knowledge and Belief with Interactions-Final Report Summary
		In particular, the focus of the project was on developing proof methods for the combination of propositional linear-time temporal logic with the modal logic S5 to represent knowledge, and allowing interaction between the modal and temporal components.
		Prior to the commencement of the project we developed resolution methods for the fusion of propositional linear-time temporal logics with the modal logic S5 for knowledge [8].
		In an alternative approach to this problem we used a translation to a fragment of first order classical logic for the modal part whilst retaining the temporal clauses in their original form to provide a resolution based decision procedure for the fusion of any normal modal logic with propositional-linear time temporal logic [18].
	www.csc.liv.ac.uk /~clare/projects/tlkbi/tlkbifinal.html (1936 words)

	The world's top modal logic websites
		The basic set of modal operators are usually given to be possibility, actuality, and necessity,.
		Also important is the term "contingent": a contingent statement is one which is not necessarily true, i.e., is possibly true, and possibly false; a contingent truth is one which is actually true, but which could have been otherwise.
		For example, K does not determine whether []p implies [][]p, i.e., it does not say whether necessary truths are necessarily necessary, or whether it is possible for them not to be necessary.
	www.websbiggest.com /wiki-article-tab.cfm/modal_logic (1782 words)

	Arché TWiki . Arche . ModalLogic
		N. Cocchiarella, "Philosophical perspectives on quantification in tense and modal logic", in GabbayHandbookOfPhilosophicalLogic, pp.
		Saul Kripke, "Semantical Considerations on Modal Logic", Acta Philosophica Fennica 16 (1963), pp.
		Bernard Linsky and Edward N. Zalta, "In Defense of the Simplest Quantified Modal Logic", Philosophical Perspectives 81 (1994), pp.
	arche-wiki.st-and.ac.uk /~ahwiki/bin/view/Arche/ModalLogic (1249 words)

	Abstracts of Joseph Y. Halpern's Publications (Site not responding. Last check: 2007-10-11)
		We discuss how the logic might be used in areas where decision making is crucial, such as management and medical diagnosis, and conclude by using LL to give a formal proof of correctness of a protocol for exchanging secrets.
		Several new logics for belief and knowledge are introduced and studied, all of which have the property that agents are not logically omniscient.
		Modal epistemic logics for many agents often assume a fixed one-to-one correspondence between agents and the names for agents that occur in the language.
	www.cs.cornell.edu /home/halpern/abstract.html (17995 words)

	[PVS] Theorem Prover for Modal Logic S5 (Site not responding. Last check: 2007-10-11)
		[PVS] Theorem Prover for Modal Logic S5 To: "Francis.Flannery" , pvs@csl.sri.com, hol-info@lists.sourceforge.net, coq-club@pauillac.inria.fr
		Yes, the modal logic S5 is strange because there is no known traditional sequent calculus for it which is cut-free.
		The Logics Work Bench at the University of Bern http://www.lwb.unibe.ch/modules/s5/index.html has a module for theorem proving in (propositional) S5.
	pvs.csl.sri.com /mail-archive/pvs/msg01355.html (365 words)

	AUTHOR INDEX
		Now temporal logics are working inside different well known formal systems and also are in stage of developing for certain new temporal systems.
		We deal with modal temporal logic which has two modalities and correspondently two binary accessibility relations L and R. The temporal configuration consists of two basic components.
		In this paper we describe a class of resolution logics P of v-degrees bounded by the cardinality of a smallest matrix that defines the same inconsistent sets of formulas as P.
	www.filozof.uni.lodz.pl /bulletin/v262.html (483 words)

	Re: modal logic (Site not responding. Last check: 2007-10-11)
		I agree what you seem to >suggest, that the minimal modal logic S5 is adequate for most cases.
		S5 is one of the strongest of all versions of modal logic, and in an earlier note, I cited the example to show that S4 is closer to the usual policy of database administrators.
		All of Kripke's semantics follows from Dunn's approach, but the philosophical and computational foundations are much clearer and more explicit.
	grouper.ieee.org /groups/suo/email/msg00126.html (233 words)

	Modal Logic System S5 (Lewis)
		In the same sense that IPC and S4 are related, Standard PC and S5 are related.
		The system S5 is the result of T and the axiom 5 [Mp>LMp] [Hughes and Cresswell, 1996]
		S5 is K sub L plus the definition: DN2: La == aandGaandHa [Rescher and Urquhart, 1971, p133]
	www.cc.utah.edu /~nahaj/logic/structures/systems/s5.html (312 words)

	The Simplest Quantified Modal Logic: A Supplement to Actualism
		The axioms and rules of inference of propositional logic, S5 modal logic, classical quantification theory, and the logic of identity are as follows, where φ, ψ, and θ are formulas, α and β variables, and τ a term of the first-order quantified modal language L.
		The Simplest Quantification Modal Logic can now be characterized succinctly by the "equation": SQML = PL + CQT + Id + ML.
		Definition: φ is a theorem of SQML if it is an axiom of SQML or follows from other theorems of SQML by a rule of inference.
	plato.stanford.edu /entries/actualism/logic.html (220 words)

	AUTHOR INDEX
		A class of modal logics with a finite model property with respect to the set of M-formulae
		Unitary Unification of S5 Modal Logic and its Extensions
		Structural completeness of modal logics containing K4 On distributivity of the lattice of subquasivarieties of a variety of Heyting algebra
	www.filozof.uni.lodz.pl /bulletin/d.html (353 words)

	[No title] (Site not responding. Last check: 2007-10-11)
		Epistemic logic is an application of modal logic, which we have previously studied, and it is used for reasoning about knowledge.
		As one of the aims of KR&R is to adequately and efficiently represent knowledge, epistemic logic provides us with a means of modelling real world problems using agent systems, as we will see.
		In S4 (and S5), each world automatically has access to itself, thus, the accessibility relation is reflexive.
	www.csc.liv.ac.uk /~katie/304-Lecture26.ppt (376 words)

	A Cut-Free Gentzen Formulation of the Modal Logic S5 - Bra (ResearchIndex) (Site not responding. Last check: 2007-10-11)
		Abstract: The goal of this paper is to introduce a new Gentzen formulation of the modal logic S5.
		However, all these systems are technically involved, and furthermore, they di#er considerably from Gentzen's original formulation of classical logic.
		A cut-free Gentzen formulation of the modal logic S5.
	citeseer.ist.psu.edu /396659.html (268 words)

	Ground Nonmonotonic Modal Logic S5: New Results -- Galindo et al. 15 (5): 787 -- Journal of Logic and Computation
		Ground Nonmonotonic Modal Logic S5: New Results -- Galindo et al.
		logics are equivalent to a nonmonotonic logic that we construct
		GNM-S5 as a reminder of its origin in the logic S5.
	logcom.oxfordjournals.org /cgi/content/short/15/5/787?rss=1 (152 words)

	Torben Braüner's Publications
		An earlier version was given at Advances in Modal Logic, Toulouse, France, 2002.
		An earlier version was given at Advances in Modal Logic/International Conference on Temporal Logic, Leipzig, Germany, 2000.
		Towards a Diagrammatic Formulation of Modal and Temporal Logic (with Peter Øhrstrøm).
	akira.ruc.dk /~torben/publications.html (858 words)

	Modal logic (Site not responding. Last check: 2007-10-11)
		The contemporary logical analysis of modality can be traced to C. Lewis's "A Survey of Symbolic Logic" (1918), in which he developed the logical systems S1-S5.
		Temporal logic is closely related to modal logic, as adding modal operators and [P, meaning, respectively, henceforth and hitherto, leads to a system of temporal logic.
		it uses material from the wikipedia article "Modal logic"
	www.33beat.com /Modal_logic.html (2221 words)

	IngentaConnect Ground Nonmonotonic Modal Logic S5: New Results (Site not responding. Last check: 2007-10-11)
		We study logic programs under Gelfond's translation in the context of modal logic S5.
		We show that for arbitrary logic programs (propositional theories where logic negation is associated with default negation) ground nonmonotonic modal logics between T and S5 are equivalent.
		Furthermore, we also show that these logics are equivalent to a nonmonotonic logic that we construct using the well known F O U R bilattice.
	ingentaconnect.com /content/oup/logcom/2005/00000015/00000005/art00787 (259 words)

Try your search on: Qwika (all wikis)