Click Here ">
« January 2005 »
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31
You are not logged in. Log in
Entries by Topic
All topics
Cognition & Epistemology
Notes on Pirah?
Ontology&possible worlds
Syn-Sem Interface
Temporal Logic
Blog Tools
Edit your Blog
Build a Blog
RSS Feed
View Profile
Translate this
LINGUISTIX&LOGIK, Tony Marmo's blog
Sunday, 2 January 2005

Now Playing: REPOSTED

Investigations in grounded semantics for multi-agent systems specification via deontic logic

By Alessio Lomuscio and Marek Sergot

We investigate an extension of the formalism of interpreted systems by Halpern and colleagues to model correct behaviour of agents. The semantical model allows for the representation and reasoning about states of correct and incorrect functioning behaviour of the agents, and of the system as a whole. We axiomatise this semantic class by mapping it into a suitable class of Kripke models. The resulting logic, KD45ni-j, is a stronger version of KD, the system often referred to as Standard Deontic Logic. We discuss these issues and present further directions of work related to epistemic Logic.


Posted by Tony Marmo at 00:01 GMT
Updated: Sunday, 2 January 2005 12:08 GMT
Saturday, 1 January 2005


Logics for Dialogue

By Alain Lecomte

This paper is essentially a survey of some logical approaches to dialogue. We start with Dialogical Logic, which was initiated by Lorenzen and has mainly been explored as a new foundation for logics. It continues with Hintikka's Game Theoretical Semantics, which has been more developed in contact with Natural Language. For instance, we show how to deal with generalized quantifiers by using games, after ideas taken from Ahti Pietarinen. The two perspectives, if different in their objectives, could be mixed for applicative purposes like the treatment of argumentative dialogues: this requires that they be recast in a neutral form, which consists in Dialogue Games in Extensive form. Nevertheless, to stay at one level of elementary language games is not sufficient: in every day life, games are combined. At this point, it seems that the Game-Theoretic interpretation of Linear Logic provides us with the appropriate tool for combining elementary games of various kinds.

See it

Posted by Tony Marmo at 00:01 GMT
Updated: Saturday, 1 January 2005 09:58 GMT
Monday, 27 December 2004


On the Logical Unsolvability of the Gettier Problem

By Luciano Floridi

The tripartite account of propositional, fallibilist knowledge that p as justified true belief can become adequate only if it can solve the Gettier Problem. However, the latter can be solved only if the problem of a successful coordination of the resources (at least truth and justification) necessary and sufficient to deliver propositional, fallibilist knowledge that p can be solved. In this paper, the coordination problem is proved to be insolvable by showing that it is equivalent to the coordinated attack problem, which is demonstrably insolvable in epistemic logic. It follows that the tripartite account is not merely inadequate as it stands, as proved by Gettier-type counterexamples, but demonstrably irreparable in principle, so that efforts to improve it can never succeed.


Posted by Tony Marmo at 00:01 GMT
Updated: Monday, 27 December 2004 01:22 GMT
Tuesday, 21 December 2004


Roles and Deontic Logic

By F. Cuppens

The objective of this paper is to propose a new semantics for a class of normative positions that applies deontic operators to descriptions of possible act-positions. This semantics is based on the concept of role which represents a behavior an agent is authorized to play. Within this new semantics, we investigate several deontic problems such as the treatment of Chisholm's Paradox, moral dilemmas and defeasible deontic reasoning.

Get it

Posted by Tony Marmo at 00:01 GMT
Updated: Tuesday, 21 December 2004 08:59 GMT
Friday, 10 December 2004


On the Complexity of Propositional Knowledge Base Revision, Updates, and Counterfactuals

By Thomas Eiter and Georg Gottlob

We study the complexity of several recently proposed methods for updating or revising propositional knowledge bases under the principle of minimal change. In particular, we derive complexity results for the following problem: given a knowledge base T, an update p, and a formula q, decide whether q is derivable from Tp, the updated (or revised) knowledge base. Note that this problem includes the evaluation of the counterfactual p > q over T, that is a conditional statement 'if p, then q' where p is known or expected to be false. We consider the general case where T is an arbitrary propositional formula (or theory) as well as restricted versions of this problem, in particular where T is a conjunction of Horn clauses, or where the size of the update p is bounded by a constant.


Related post

Posted by Tony Marmo at 00:01 GMT
Updated: Tuesday, 7 December 2004 23:02 GMT
Sunday, 21 November 2004


First - and Second-Order Logic of Mass Terms

By Peter Roeper

The logic of mass terms is a generalisation of standard predicate logic. It allows for domains of quantification which have parts, but do not consist of individuals. The rules of inference are largely those of normal predicate logic. The main point of divergence concerns the identification of argument places (reflexivisation). As there may be no individuals, the idea that distinct occurrences of the same variable always refer to the same individual cannot be applied in specifying the semantics.

The first -order system is developed syntactically in Section 1, the second-order system in Section 2. Formal semantics for the logic of mass terms 1are arrived at indirectly by first translating the statements of the logic of mass terms into a standard first -order calculus, whose domain of quantification is the totality of quantities, i.e. the totality of parts of the domain of mass quantification.

Soundness and completeness results for the first -order logic of mass terms are obtained in Section 3, for second-order logic in Section 4.

Published in the Journalof Philosophical Logic 33(2004)261-297
The paper

Posted by Tony Marmo at 00:01 GMT
Updated: Thursday, 25 November 2004 05:07 GMT
Friday, 12 November 2004


Tarski's Conception of Logic

By Solomon Feferman

In its widest scope, Tarski thought the aims of logic should be the creation of a unified conceptual apparatus which would supply a common basis for the whole of human knowledge. Those were his very words in the Preface to the first English edition of the Introduction to Logic (1940). Toward that grand end, in the post-war years when the institutional and financial resources became available, with extraordinary persistence and determination Tarski campaigned vigorously on behalf of logic on several fronts from his increasingly powerful base at the University of California in Berkeley.(...)


Posted by Tony Marmo at 00:01 GMT
Updated: Thursday, 28 October 2004 18:52 BST
Thursday, 11 November 2004


Axiomatizing Modal Theories of Subset Spaces
(An Example of the Power of Hybrid Logic)

By Bernhard Heinemann

This paper is about a synthesis of two quite different modal reasoning formalisms: the logic of subset spaces, and hybrid logic. Going beyond commonly considered languages we introduce names of objects involving sets and corresponding satisfaction operators. In this way we are able to completely axiomatize the theory of certain classes of subset spaces which are difficult to deal with purely modally. We also study effectivity properties of the resulting logical systems.

Get it

Posted by Tony Marmo at 00:01 GMT
Updated: Thursday, 11 November 2004 10:06 GMT
Saturday, 6 November 2004


When does `everything' mean everything?

By Agustin Rayo

At least two different lines of resistance might be deployed against the view that it is possible to quantify over absolutely everything. According to the first, there is no such a thing as an all-inclusive domain. In contrast, the second line of resistance concedes - at least for the sake of argument - that there is such a thing as an all-inclusive domain, but insists that nothing in an agent's thoughts and practices could ever uniquely determine that her domain of quantification is all-inclusive. For whenever it is compatible with an agent's thoughts and practices that his domain of quantification is all-inclusive, it is also compatible with his thoughts and practices that his domain of quantification is less-than-all-inclusive. So the agent could never be said to determinately quantify over absolutely everything. In this paper, I will argue that, when the first line of resistance is set aside, there are reasons for thinking that determinate unrestricted quantification is possible. I will have nothing to say about the first line of resistance.


Posted by Tony Marmo at 00:01 GMT
Updated: Monday, 1 November 2004 07:28 GMT
Wednesday, 27 October 2004


Grim on Vagueness

The text introduced hereinafter could easily be a paper on the semantics of any natural language, such as Latin, English, Spanish, Korean or French. As the reader can see by the specific topic, which is approached by Grim, issues respecting greater philosophical discussions often have to do with puzzles in Linguistics:

The buried quantifier:
an account of vagueness and the sorites

By Patrick Grim

Contrary to the great bulk of philosophical work on vagueness, the core of vagueness is not to be found in vague monadic predicates such as bald, tall, or old. The true source of vagueness - at least vagueness of the type that typically appears in the sorites - lies beneath these, in a mechanism using a buried quantifier operative over the comparatives balder, taller and older.

Or so I propose. Here the quantifier account is presented in its simplest form, with the limited claim that it offers a paradigmatic treatment for paradigmatic vague predicates in the sorites. Questions remain as to whether the account or something like it can be extended to all sorites vulnerable predicates, and qualifications and concessions in this regard are offered in ?9. What the approach promises, however, even in this limited form, is deeper understanding of vagueness through a deeper understanding of non-comparative adjectives derived from comparatives, a central explanation for a range of otherwise puzzling and disparate phenomena, and a new resolution for the sorites.

Source: Analysis Preprints

Go on

It is interesting to notice that in the Semantics of natural languages the question of whether there are covert quantifiers or operators is a top issue nowadays. Their proponents consider that they are necessary to explain many facts associated with the interpretation of sentences.

Posted by Tony Marmo at 00:01 BST
Updated: Tuesday, 26 October 2004 00:04 BST
Tuesday, 26 October 2004


Some more curious inferences

By Jeffrey Ketland

Nominalism denies the existence of numbers, sets and functions. But a widely discussed problem concerns whether nominalism can account for the applicability of mathematics. This is the indispensability argument against nominalism, associated with Godel, Quine and Putnam. Above we examined examples of the application of mathematics to relationships of logical consequence. It seems to me that the `speed-up' phenomenon under discussion suggests a modified version of the indispensability argument, based now on unfeasibility considerations. Presumably the nominalist does not wish to deny the validity of the inferences I, I{2}, and I{3} under consideration. But there is no feasible direct verification for the above inferences, and the short mathematical derivations involve practically indispensable assumptions about numbers, sets and functions. So, how might a nominalist account for our knowledge that such inferences are valid? After all, the anecdotal evidence is that even nonmathematicians find I{2} and I{3} `obvious'.

Source: Analysis Preprints

See more

Setting aside the problems Ketland mentions above, Everett could try to write a Nominalist Semantics for Pirah?, for that would be consistent with Everett's recent works. Nevertheless, in such case any claim Everett made in the case of Pirah? would have to be valid for other natural languages, and, of course, his views would not easily convince those who do not accept nominalism.

Posted by Tony Marmo at 00:01 BST
Updated: Wednesday, 27 October 2004 00:00 BST
Tuesday, 19 October 2004


Lockean and Logical Truth Conditions

By James Dreier
Source: Online Papers in Philosophy

The distinction between logical and Lockean truth conditions helps Expressivism to distinguish itself from Subjectivism. Expressivism is the view that moral judgements lack logical truth conditions. Subjectivism says that moral judgements have logical truth conditions involving the speaker's attitudes. Both theories may allow that moral judgements have Lockean truth conditions involving the speaker's attitudes.

See more

Posted by Tony Marmo at 00:01 BST
Updated: Tuesday, 19 October 2004 05:18 BST
Wednesday, 29 September 2004


What is a Correspondence Theory of Truth?

By Douglas Patterson
Source: Synthese

It is often thought that instances of the T-schema such as `` `snow is white' is true if and only if snow is white'' state correspondences between sentences and the world, and that therefore such sentences play a crucial role in correspondence theories of truth. I argue that this assumption trivializes the correspondence theory: even a disquotational theory of truth would be a correspondence theory on this conception. This discussion allows one to get clearer about what a correspondence theory does claim, and toward the end of the paper I discuss what a true correspondence theory of truth would involve.


Posted by Tony Marmo at 01:01 BST
Updated: Monday, 27 September 2004 18:11 BST
Sunday, 26 September 2004


On the Notion of Substitution

Marcel Crabbe

We consider a concept of substitutive structure, called "logos", in order to study simple substitution, independently of formal or programming languages. We provide a definition of simultaneous substitution in an arbitrary logos and use it to prove a completeness theorem expressing that the equational properties of the usual substitution can be proved from the logos axioms only.


Posted by Tony Marmo at 01:01 BST
Updated: Saturday, 25 September 2004 07:25 BST
Monday, 20 September 2004

The debate goes on: how many truth-values are necessary in Logic?

Truth, Falsity and Borderline Cases

by Miroslava Andjelkovi & Timothy Williamson

According to the principle of bivalence, truth and falsity are jointly exhaustive and mutually exclusive options for a statement. It is either true or false, and not both, even in a borderline case.
That highly controversial claim is central to the epistemic theory of vagueness, which holds that borderline cases are distinguished by a special kind of obstacle to knowing the truth -value of the statement. But this paper is not a defence of the epistemic theory. If bivalence holds, it presumably does so as a consequence of what truth and falsity separately are.
One may therefore expect bivalence to be derivable from a combination of some principles characterizing truth and other principles characterizing falsity. Indeed, such derivations are easily found. Their form will of course depend on the initial characterizations of truth and falsity, and not all such characterizations will permit bivalence to be derived. In this paper we focus on the relation between its derivability and some principles about truth and falsity . We will use borderline cases for vague expressions as primary examples of an urgent challenge to bivalence.


For the debate of the issue, see Pelletier and Stainton?s paper On `The Denial of Bivalence is Absurd'.

Posted by Tony Marmo at 07:39 BST

Newer | Latest | Older