Jason Stanley

CONTEXT AND LOGICAL FORM

In this paper, I defend the thesis that alleffects of extra-linguistic context on the truth-conditions of an assertion are traceable to elements in the actual syntactic structure of the sentence uttered. In the first section, I develop the thesis in detail, and discuss its implications for the relation between semantics and pragmatics. The next two sections are devoted to apparent counterexamples. In the second section, I argue that there are no convincing examples of true non-sentential assertions. In the third section, I argue that there are no convincing examples of what John Perry has called ‘unarticulated constituents’. I conclude by drawing some consequences of my arguments for appeals to context-dependence in the resolution of problems in epistemology and philosophical logic.

Making it Articulated

I argue in favor of the view that all the constituents of the propositions hearers would intuitively believe to be expressed by utterances are the result of assigning values to the elements of the sentence uttered, and combining them in accord with its structure. The way I accomplish this is by questioning the existence of some of the processes that theorists have claimed underlie the provision of constituents to the propositions recovered by hearers in linguistic interpretation, processes that apparently bypass assigning these constituents to elements of the logical form of the expression uttered.

On the linguistic basis for contextualism

descendant of the original paper (Stanley (forthcoming)) focuses on developing a noncontextualist account of knowledge that captures the intuitive data as well as contextualism. Discussion with the participants at the conference at the University of Massachusetts was very helpful. I should single out John Hawthorne and my commentator Barbara Partee for special mention; e-mails with Stewart Cohen since then have also been invaluable. I am also indebted for discussion to Herman Cappelen, Keith DeRose, Tamar Gendler, Richard Heck, Jim Joyce, Chris Kennedy, Jeffrey King, Ernie Lepore, Peter Ludlow, Robert Stalnaker, and Timothy Williamson.

Motor skill depends on knowledge of facts

Those in 20th century philosophy, psychology, and neuroscience who have discussed the nature of skilled action have, for the most part, accepted the view that being skilled at an activity is independent of knowing facts about that activity, i.e., that skill is independent of knowledge of facts. In this paper we question this view of motor skill. We begin by situating the notion of skill in historical and philosophical context. We use the discussion to explain and motivate the view that motor skill depends upon knowledge of facts. This conclusion seemingly contradicts well-known results in cognitive science. It is natural, on the face of it, to take the case of H.M., the seminal case in cognitive neuroscience that led to the discovery of different memory systems, as providing powerful evidence for the independence of knowledge and skill acquisition. After all, H.M. seems to show that motor learning is retained even when previous knowledge about the activity has been lost. Improvements in skill generally require increased precision of selected actions, which we call motor acuity. Motor acuity may indeed not require propositional knowledge and has direct parallels with perceptual acuity. We argue, however, that reflection on the specifics of H.M.s case, as well as other research on the nature of skill, indicates that learning to become skilled at a motor task, for example tennis, depends also on knowledge-based selection of the right actions. Thus skilled activity requires both acuity and knowledge, with both increasing with practice. The moral of our discussion ranges beyond debates about motor skill; we argue that it undermines any attempt to draw a distinction between practical and theoretical activities. While we will reject the independence of skill and knowledge, our discussion leaves open several different possible relations between knowledge and skill. Deciding between them is a task to be resolved by future research.

Context, interest relativity and the sorites

According to what I will call a contextualist solution to the sorites paradox, vague terms are context-sensitive, and one can give a convincing dissolution of the sorites paradox in terms of this context-dependency. The reason, according to the contextualist, that precise boundaries for expressions like ‘heap’ or ‘tall for a basketball player’ are so difficult to detect is that when two entities are sufficiently similar (or saliently similar), we tend to shift the interpretation of the vague expression so that if one counts as falling in the extension of the property expressed by that expression, so does the other. As a consequence, when we look for the boundary of the extension of a vague expression in its penumbra, our very looking has the effect of changing the interpretation of the vague expression so that the boundary is not where we are looking. This accounts for the persuasive force of sorites arguments. Suppose we are presented with fifty piles each of which has one grain less than the pile to its left. On the far left is a pile we are strongly inclined to call a heap when presented alone. This pile is in the definite extension of ‘heap’. On the far right is a pile we are slightly inclined not to call a heap when presented alone. It is towards the end of the penumbra of ‘heap’. But starting with the left-most pile (pile 1), we may make progressive judgements of the form:

Concurrency bugs in multithreaded software: modeling and analysis using Petri nets

In this paper, we apply discrete-event system techniques to model and analyze the execution of concurrent software. The problem of interest is deadlock avoidance in shared-memory multithreaded programs. We employ Petri nets to systematically model multithreaded programs with lock acquisition and release operations. We define a new class of Petri nets, called Gadara nets, that arises from this modeling process. We investigate a set of important properties of Gadara nets, such as liveness, reversibility, and linear separability. We propose efficient algorithms for the verification of liveness of Gadara nets, and report experimental results on their performance. We also present modeling examples of real-world programs. The results in this paper lay the foundations for the development of effective control synthesis algorithms for Gadara nets.

Eliminating Concurrency Bugs in Multithreaded Software: A New Approach Based on Discrete-Event Control

Computer hardware is moving from uniprocessor to multicore architectures. One problem arising in this evolution is that only parallel software can exploit the full performance potential of multicore architectures, and parallel software is far harder to write than conventional serial software. One important class of failures arising in parallel software is circular-wait deadlock in multithreaded programs. In our ongoing Gadara project, we use a special class of Petri nets, called Gadara nets, to systematically model multithreaded programs with lock allocation and release operations. In this paper, we propose an efficient optimal control synthesis methodology for ordinary Gadara nets that exploits the structural properties of Gadara nets via siphon analysis. Optimality in this context refers to the elimination of deadlocks in the program with minimally restrictive control logic. We formally establish a set of important properties of the proposed control synthesis methodology, and show that our algorithms never synthesize redundant control logic. We conduct experiments to evaluate the efficiency and scalability of the proposed methodology, and discuss the application of our results to real-world concurrent software.

Deadlock-avoidance control of multithreaded software: An efficient siphon-based algorithm for Gadara petri nets

This paper presents an efficient implementation of an iterative control algorithm for the synthesis of maximally-permissive liveness-enforcing control policies for Gadara nets presented in earlier work. Gadara nets are a special class of Petri nets arising when modeling multithreaded software for the purpose of deadlock analysis and resolution. The considered control synthesis algorithm is based on structural analysis of Gadara nets in terms of a certain type of siphons, called resource-induced deadly-marked siphons. We propose a new customized mixed integer programming formulation to detect these siphons in Gadara nets. We then compare the performance of our customized algorithm with that of a generic siphon detection algorithm for process-resource nets in the context of the iterative control algorithm. Finally, we investigate the scalability of the overall algorithm to large program models.

Understanding, context‐relativity, and the Description Theory

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Explicit storage and analysis of billions of states using commodity computers

Abstract The objective of this paper is to develop a framework and associated algorithms for explicit state space exploration of discrete event systems that can scale to very large state spaces. We consider classes of resource allocation systems (RAS), where a set of resources are shared by concurrent processes. In particular, we focus on Gadara RAS, whose Petri net representations have recently been used for liveness enforcement in multithreaded software. We present a framework where each reachable state of the RAS is represented by a single bit. We show how single-bit representations can lead to efficient implementations of supervisory control algorithms. In order to support single-bit state representations, we develop two indexing functions that map each state to a unique integer that serves as the corresponding index of the state in the large bit array. These functions exploit the invariants of the given RAS. Experimental results show that our techniques scale up to exploration and analysis of billions of states on commodity computers.