173 research outputs found
A substructural modal logic of utility
We introduce a substructural modal logic of utility that can be used to reason aboutoptimality with respect to properties of states. Our notion of state is quite general, and is able to represent resource allocation problems in distributed systems. The underlying logic is a variant of the modal logic of bunched implications, and based on resource semantics, which is closely related to concurrent separation logic. We consider a labelled transition semantics and establish conditions under which Hennessy—Milner soundness and completeness hold. By considering notions of cost, strategy and utility, we are able to formulate characterizations of Pareto optimality, best responses, and Nash equilibrium within resource semantics. We also show that our logic is able to serve as a logic for a fully featured process algebra and explain the interaction between utility and the structure of processes
Tool support for reasoning in display calculi
We present a tool for reasoning in and about propositional sequent calculi.
One aim is to support reasoning in calculi that contain a hundred rules or
more, so that even relatively small pen and paper derivations become tedious
and error prone. As an example, we implement the display calculus D.EAK of
dynamic epistemic logic. Second, we provide embeddings of the calculus in the
theorem prover Isabelle for formalising proofs about D.EAK. As a case study we
show that the solution of the muddy children puzzle is derivable for any number
of muddy children. Third, there is a set of meta-tools, that allows us to adapt
the tool for a wide variety of user defined calculi
Intuitionistic layered graph logic
Models of complex systems are widely used in the physical and social sciences, and the concept of layering, typically building upon graph-theoretic structure, is a common feature. We describe an intuitionistic substructural logic that gives an account of layering. As in bunched systems, the logic includes the usual intuitionistic connectives, together with a non-commutative, non-associative conjunction (used to capture layering) and its associated implications. We give soundness and completeness theorems for labelled tableaux and Hilbert-type systems with respect to a Kripke semantics on graphs. To demonstrate the utility of the logic, we show how to represent a range of systems and security examples, illuminating the relationship between services/policies and the infrastructures/architectures to which they are applied
Conjuntos construibles en modelos valuados en retĂculos
We investigate different set-theoretic constructions in Residuated Logic based on Fitting’s
work on Intuitionistic Kripke models of Set Theory.
Firstly, we consider constructable sets within valued models of Set Theory. We present
two distinct constructions of the constructable universe: L
B and L
B
, and prove that the
they are isomorphic to V (von Neumann universe) and L (Gödel’s constructible universe),
respectively.
Secondly, we generalize Fitting’s work on Intuitionistic Kripke models of Set Theory using
Ono and Komori’s Residuated Kripke models. Based on these models, we provide a general-
ization of the von Neumann hierarchy in the context of Modal Residuated Logic and prove
a translation of formulas between it and a suited Heyting valued model. We also propose a
notion of universe of constructable sets in Modal Residuated Logic and discuss some aspects
of it.Investigamos diferentes construcciones de la teorĂa de conjuntos en LĂłgica Residual basados
en el trabajo de Fitting sobre los modelos intuicionistas de Kripke de la TeorĂa de Conjuntos.
En primer lugar, consideramos conjuntos construibles dentro de modelos valuados de la
TeorĂa de Conjuntos. Presentamos dos construcciones distintas del universo construible:
L
B y L
B
, y demostramos que son isomorfos a V (universo von Neumann) y L (universo
construible de Gödel), respectivamente.
En segundo lugar, generalizamos el trabajo de Fitting sobre los modelos intuicionistas de
Kripke de la teorĂa de conjuntos utilizando los modelos residuados de Kripke de Ono y
Komori. Con base en estos modelos, proporcionamos una generalizaciĂłn de la jerarquĂa de
von Neumann en el contexto de la LĂłgica Modal Residuada y demostramos una traducciĂłn de
fórmulas entre ella y un modelo Heyting valuado adecuado. También proponemos una noción
de universo de conjuntos construibles en LĂłgica Modal Residuada y discutimos algunos
aspectos de la misma. (Texto tomado de la fuente)MaestrĂaMagĂster en Ciencias - MatemáticasLĂłgica matemática, teorĂa de conjunto
Changing a semantics: opportunism or courage?
The generalized models for higher-order logics introduced by Leon Henkin, and
their multiple offspring over the years, have become a standard tool in many
areas of logic. Even so, discussion has persisted about their technical status,
and perhaps even their conceptual legitimacy. This paper gives a systematic
view of generalized model techniques, discusses what they mean in mathematical
and philosophical terms, and presents a few technical themes and results about
their role in algebraic representation, calibrating provability, lowering
complexity, understanding fixed-point logics, and achieving set-theoretic
absoluteness. We also show how thinking about Henkin's approach to semantics of
logical systems in this generality can yield new results, dispelling the
impression of adhocness. This paper is dedicated to Leon Henkin, a deep
logician who has changed the way we all work, while also being an always open,
modest, and encouraging colleague and friend.Comment: 27 pages. To appear in: The life and work of Leon Henkin: Essays on
his contributions (Studies in Universal Logic) eds: Manzano, M., Sain, I. and
Alonso, E., 201
Compositional Reasoning for Explicit Resource Management in Channel-Based Concurrency
We define a pi-calculus variant with a costed semantics where channels are
treated as resources that must explicitly be allocated before they are used and
can be deallocated when no longer required. We use a substructural type system
tracking permission transfer to construct coinductive proof techniques for
comparing behaviour and resource usage efficiency of concurrent processes. We
establish full abstraction results between our coinductive definitions and a
contextual behavioural preorder describing a notion of process efficiency
w.r.t. its management of resources. We also justify these definitions and
respective proof techniques through numerous examples and a case study
comparing two concurrent implementations of an extensible buffer.Comment: 51 pages, 7 figure
Phase Semantics for Linear Logic with Least and Greatest Fixed Points
The truth semantics of linear logic (i.e. phase semantics) is often overlooked despite having a wide range of applications and deep connections with several denotational semantics. In phase semantics, one is concerned about the provability of formulas rather than the contents of their proofs (or refutations). Linear logic equipped with the least and greatest fixpoint operators (?MALL) has been an active field of research for the past one and a half decades. Various proof systems are known viz. finitary and non-wellfounded, based on explicit and implicit (co)induction respectively.
In this paper, we extend the phase semantics of multiplicative additive linear logic (a.k.a. MALL) to ?MALL with explicit (co)induction (i.e. ?MALL^{ind}). We introduce a Tait-style system for ?MALL called ?MALL_? where proofs are wellfounded but potentially infinitely branching. We study its phase semantics and prove that it does not have the finite model property
Resource semantics: logic as a modelling technology
The Logic of Bunched Implications (BI) was introduced by O'Hearn and Pym. The original presentation of BI emphasised its role as a system for formal logic (broadly in the tradition of relevant logic) that has some interesting properties, combining a clean proof theory, including a categorical interpretation, with a simple truth-functional semantics. BI quickly found significant applications in program verification and program analysis, chiefly through a specific theory of BI that is commonly known as 'Separation Logic'. We survey the state of work in bunched logics - which, by now, is a quite large family of systems, including modal and epistemic logics and logics for layered graphs - in such a way as to organize the ideas into a coherent (semantic) picture with a strong interpretation in terms of resources. One such picture can be seen as deriving from an interpretation of BI's semantics in terms of resources, and this view provides a basis for a systematic interpretation of the family of bunched logics, including modal, epistemic, layered graph, and process-theoretic variants, in terms of resources. We explain the basic ideas of resource semantics, including comparisons with Linear Logic and ideas from economics and physics. We include discussions of BI's λ-calculus, of Separation Logic, and of an approach to distributed systems modelling based on resource semantics
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