共查询到20条相似文献,搜索用时 31 毫秒
1.
Two groups of agents, and , face a moral conflict if has a moral obligation and has a moral obligation, such that these obligations cannot both be fulfilled. We study moral conflicts using a multi-agent
deontic logic devised to represent reasoning about sentences like ‘In the interest of group of agents, group of agents ought to see to it that .’ We provide a formal language and a consequentialist semantics. An illustration of our semantics with an analysis of the
Prisoner’s Dilemma follows. Next, necessary and sufficient conditions are given for (1) the possibility that a single group
of agents faces a moral conflict, for (2) the possibility that two groups of agents face a moral conflict within a single
moral code, and for (3) the possibility that two groups of agents face a moral conflict. 相似文献
2.
This paper presents a calculus for mereotopological reasoning in which two-dimensional spatial regions are treated as primitive entities. A first order predicate language
with a distinguished unary predicate c(x), function-symbols , · and – and constants 0 and 1 is defined. An interpretation
for
is provided in which polygonal open subsets of the real plane serve as elements of the domain. Under this interpretation the predicate c(x) is read as region x is connected and the function-symbols and constants are given their meaning in terms of a Boolean algebra of polygons. We give an alternative interpretation
based on the real closed plane which turns out to be isomorphic to
A set of axioms and a rule of inference are introduced. We prove the soundness and completeness of the calculus with respect to the given interpretation. 相似文献
3.
J. Michael Dunn 《Studia Logica》1979,38(2):149-169
Given classical (2 valued) structures
and
and a homomorphism h of
onto
, it is shown how to construct a (non-degenerate) 3-valued counterpart
of
. Classical sentences that are true in
are non-false in
. Applications to number theory and type theory (with axiom of infinity) produce finite 3-valued models in which all classically true sentences of these theories are non-false. Connections to relevant logic give absolute consistency proofs for versions of these theories formulated in relevant logic (the proof for number theory was obtained earlier by R. K. Meyer and suggested the present abstract development). 相似文献
4.
Heinrich Wansing 《Journal of Philosophical Logic》2006,35(6):653-660
Many logical systems are such that the addition of Prior's binary connective to them leads to triviality, see [1, 8]. Since is given by some introduction and elimination rules in natural deduction or sequent rules in Gentzen's sequent calculus, the unwanted effects of adding show that some kind of restriction has to be imposed on the acceptable operational inferences rules, in particular if these rules are regarded as definitions of the operations concerned. In this paper, a number of simple observations is made showing that the unwanted phenomenon exemplified by in some logics also occurs in contexts in which
is acceptable. In fact, in any non-trivial context, the acceptance of arbitrary introduction rules for logical operations permits operations leading to triviality. Connectives that in all non-trivial contexts lead to triviality will be called non-trivially trivializing connectives. 相似文献
5.
Marta A. Zander 《Studia Logica》2008,88(2):233-246
In this paper we prove that, for n > 1, the n-generated free algebra in any locally finite subvariety of HoRA can be written in a unique nontrivial way as Ł2 × A′, where A′ is a directly indecomposable algebra in . More precisely, we prove that the unique nontrivial pair of factor congruences of is given by the filters and , where the element is recursively defined from the term introduced by W. H. Cornish. As an additional result we obtain a characterization of minimal irreducible filters of in terms of its coatoms.
Presented by Daniele Mundici 相似文献
6.
We investigate an expansion of quasi-MV algebras ([10]) by a genuine quantum unary operator. The variety of such
quasi-MV algebras has a subquasivariety whose members—called cartesian—can be obtained in an appropriate way out of MV algebras. After showing that cartesian . quasi-MV algebras generate ,we prove a standard completeness theorem for w.r.t. an algebra over the complex numbers.
Presented by Heinrich Wansing 相似文献
7.
Marc Pauly 《Synthese》2007,158(2):233-250
We investigate under what conditions a given set of collective judgments can arise from a specific voting procedure. In order
to answer this question, we introduce a language similar to modal logic for reasoning about judgment aggregation procedures.
In this language, the formula
expresses that is collectively accepted, or that is a group judgment based on voting. Different judgment aggregation procedures may be underlying the group decision making.
Here we investigate majority voting, where holds if a majority of individuals accepts, consensus voting, where holds if all individuals accept, and dictatorship. We provide complete axiomatizations for judgment sets arising from all three aggregation procedures. 相似文献
8.
9.
We present some equivalent conditions for a quasivariety of structures to be generated by a single structure. The first such condition, called the embedding property was found by A.I. Mal′tsev in [6]. It says that if are nontrivial, then there exists such that A and B are embeddable into C. One of our equivalent conditions states that the set of quasi-identities valid in is closed under a certain Gentzen type rule which is due to J. Łoś and R. Suszko [5].
Presented by Jacek Malinowski 相似文献
10.
S. K. Thomason 《Journal of Philosophical Logic》1989,18(1):43-67
Conclusions and conjectures Some may be of the opinion that one event can begin before another only by virtue of the existence of some event (a witness) which wholly precedes the other and does not wholly precede the one (and similarly for ends before and does not abut). Those would prefer
0 to
as a model for observers' apprehensions of events. Since G is a functor from
to
0, the current construction (restricted to
0) remains applicable.This work supports a claim that the psychologically fundamental temporal relationships are wholly precedes, begins before, ends before and abuts. But only in a very weak sense. Any other set of relationships which is interdefinable with this one, using only quantifier-free formulas in the definitions, could be used to define a category
which is indistinguishable from
(because the same functions preserve and reflect the new relationships). This work equally supports the claim that those relationships are the psychologically fundamental ones, or the claim that it is just wholly precedes which is fundamental, and that we perceive begins before just by virtue of witnesses. But it refutes the claim that only wholly precedes is fundamental, and that we understand begins before only because we understand time as a linear ordering. 相似文献
11.
Katalin Bimbó 《Journal of Philosophical Logic》2005,34(5-6):607-620
The implicational fragment of the relevance logic “ticket entailment” is closely related to the so-called hereditary right
maximal terms. I prove that the terms that need to be considered as inhabitants of the types which are theorems of T→ are in normal form and built in all but one case from
and
only. As a tool in the proof ordered term rewriting systems are introduced. Based on the main theorem I define FIT→ – a Fitch-style calculus (related to FT→) for the implicational fragment of ticket entailment. 相似文献
12.
Xuefeng Wen 《Studia Logica》2007,85(2):251-260
We construct a a system PLRI which is the classical propositional logic supplied with a ternary construction , interpreted as the intensional identity of statements and in the context . PLRI is a refinement of Roman Suszko’s sentential calculus with identity (SCI) whose identity connective is a binary one.
We provide a Hilbert-style axiomatization of this logic and prove its soundness and completeness with respect to some algebraic
models. We also show that PLRI can be used to give a partial solution to the paradox of analysis.
Presented by Jacek Malinowski 相似文献
13.
Jarosław Achinger 《Studia Logica》1986,45(3):293-300
Universality of generalized Alexandroff's cube
plays essential role in theory of absolute retracts for the category of , -closure spaces. Alexandroff's cube.
is an , -closure space generated by the family of all complete filters. in a lattice of all subsets of a set of power
.Condition P(, ,
) says that
is a closure space of all , -filters in the lattice (
),
.Assuming that P (, ,
) holds, in the paper [2], there are given sufficient conditions saying when an , -closure space is an absolute retract for the category of , -closure spaces (see Theorems 2.1 and 3.4 in [2]).It seems that, under assumption that P (, ,
) holds, it will be possible to givean uniform characterization of absolute retracts for the category of , -closure-spaces.Except Lemma 3.1 from [1], there is no information when the condition P (, ,
) holds or when it does not hold.The main result of this paper says, that there are examples of cardinal numbers, , ,
such that P (, ,
) is not satisfied.Namely it is proved, using elementary properties of Lebesgue measure on the real line, that the condition P (,
1, 2
) is not satisfied.Moreover it is shown that fulfillment of the condition is essential assumption in, Theorems 2.1 and 3.4 from [1] i.e. it cannot be eliminated. 相似文献
14.
Robert Goldblatt 《Studia Logica》1985,44(4):423-437
A foundational algebra (
, f, ) consists of a hemimorphism f on a Boolean algebra
with a greatest solution to the condition f(x). The quasi-variety of foundational algebras has a decidable equational theory, and generates the same variety as the complex algebras of structures (X, R), where f is given by R-images and is the non-wellfounded part of binary relation R.The corresponding results hold for algebras satisfying =0, with respect to complex algebras of wellfounded binary relations. These algebras, however, generate the variety of all (
,f) with f a hemimorphism on
).Admitting a second hemimorphism corresponding to the transitive closure of R allows foundational algebras to be equationally defined, in a way that gives a refined analysis of the notion of diagonalisable algebra.The research reported in this paper was carried out while the author was at the Department of Mathematics and Statistics, University of Auckland, under a teaching exchange with the Victoria University of Wellington. 相似文献
15.
First we show that the classical two-player semantic game actually corresponds to a three-valued logic. Then we generalize
this result and give an n-player semantic game for an n + 1-valued logic with n binary connectives, each associated with a player. We prove that player i has a winning strategy in game if and only if the truth value of is t
i
in the model M, for 1 ≤ i ≤ n; and none of the players has a winning strategy in if and only if the truth value of is t
0 in M. 相似文献
16.
Sato Kentaro 《Studia Logica》2008,88(2):295-324
We study filters in residuated structures that are associated with congruence relations (which we call -filters), and develop a semantical theory for general substructural logics based on the notion of primeness for those filters.
We first generalize Stone’s sheaf representation theorem to general substructural logics and then define the primeness of
-filters as being “points” (or stalkers) of the space, the spectrum, on which the representing sheaf is defined. Prime FL-filters
will turn out to coincide with truth sets under various well known semantics for certain substructural logics. We also investigate
which structural rules are needed to interpret each connective in terms of prime -filters in the same way as in Kripke or Routley-Meyer semantics. We may consider that the set of the structural rules that
each connective needs in this sense reflects the difficulty of giving the meaning of the connective. A surprising discovery
is that connectives , ⅋ of linear logic are linearly ordered in terms of the difficulty in this sense.
Presented by Wojciech Buszkowski 相似文献
17.
We introduce two simple empirical approximate Bayes estimators (EABEs)—
and
—for estimating domain scores under binomial and hypergeometric distributions, respectively. Both EABEs (derived from corresponding marginal distributions of observed test scorex without relying on knowledge of prior domain score distributions) have been proven to hold -asymptotic optimality in Robbins' sense of convergence in mean. We found that, where
and
are the monotonized versions of
and
under Van Houwelingen's monotonization method, respectively, the convergence rate of the overall expected loss of Bayes risk in either
or
depends on test length, sample size, and ratio of test length to size of domain items. In terms of conditional Bayes risk,
and
outperform their maximum likelihood counterparts over the middle range of domain scales. In terms of mean-squared error, we also found that: (a) given a unimodal prior distribution of domain scores,
performs better than both
and a linear EBE of the beta-binomial model when domain item size is small or when test items reflect a high degree of heterogeneity; (b)
performs as well as
when prior distribution is bimodal and test items are homogeneous; and (c) the linear EBE is extremely robust when a large pool of homogeneous items plus a unimodal prior distribution exists.The authors are indebted to both anonymous reviewers, especially Reviewer 2, and the Editor for their invaluable comments and suggestions. Thanks are also due to Yuan-Chin Chang and Chin-Fu Hsiao for their help with our simulation and programming work. 相似文献
18.
Nicholas Long Barbara-Jeanne Austin Mary M. Gound Abesie O. Kelly Adrienne A. Gardner Rick Dunn Stacy B. Harris Kim S. Miller 《Journal of child and family studies》2004,13(1):47-65
The Parents Matter! Program (PMP) has developed three interventions for parents of 4th and 5th grade African-American children (9–12 years old). The overarching goal of all three interventions is to provide parents with knowledge, skills, and support for enhancing their efforts to raise healthy children. The interventions are: (1) Enhanced Communication and Parenting (five 2
-hour sessions), (2) Brief Communication and Parenting (single 2
-hour session), and (3) General Health (single 2
-hour session). This article discusses the development of these interventions, presents an overview of the content of each intervention, and discusses issues related to the facilitation/presentation of these interventions. 相似文献
19.
Fernando Guzmán 《Studia Logica》1994,53(2):243-257
Conditional logic is the deductive system
, where
is the set of propositional connectives {, ,} and is the structural finitary consequence relation on the absolutely free algebra
that preserves degrees of truth over the structure of truth values C, . HereC is the non-commutative regular extension of the 2-element Boolean algebra to 3 truth values {t, u, f}, andf<u<t. In this paper we give a Gentzen type axiomatization for conditional logic.Presented byJan Zygmunt 相似文献
20.
Ming Hsiung 《Journal of Philosophical Logic》2008,37(4):299-317
By introducing the intensional mappings and their properties, we establish a new semantical approach of characterizing intermediate
logics. First prove that this new approach provides a general method of characterizing and comparing logics without changing
the semantical interpretation of implication connective. Then show that it is adequate to characterize all Kripke_complete
intermediate logics by showing that each of these logics is sound and complete with respect to its (unique) ‘weakest characterization
property’ of intensional mappings. In particular, we show that classical logic has the weakest characterization property , which is the strongest among all possible weakest characterization properties of intermediate logics. Finally, it follows
from this result that a translation is an embedding of classical logic into intuitionistic logic, iff. its semantical counterpart
has the property .
相似文献