Afterword: Federalism’s Options

Several of the essays in this symposium, Constructing a New Federalism: Jurisdictional Competition and Competence, illustrate the current framework in which debates within the United States about federalism—be it legislative, judicial, or executive—proceed. The task at hand is to consider (from a rich range of perspectives) whether a particular arena about which laws are made (be it torts, the environment, or welfare) belongs either to state or to federal governance, or when overlapping regulatory regimes and judicial decision making are permissible. While the limits of either state or federal powers are not fixed, and the doctrinal and policy arguments change somewhat, the pervasive sense is that preexisting (albeit vague and contested) boundaries and options exist; opportunities for invention are not generous

Afterword: Federalism\u27s Options

Several of the essays in this symposium, Constructing a New Federalism: Jurisdictional Competition and Competence, illustrate the current framework in which debates within the United States about federalism-be it legislative, judicial, or executive-proceed. The task at hand is to consider (from a rich range of perspectives) whether a particular arena about which laws are made (be it torts, the environment, or welfare) belongs either to state or to federal governance, or when overlapping regulatory regimes and judicial decision making are permissible. While the limits of either state or federal powers are not fixed, and the doctrinal and policy arguments change somewhat, the pervasive sense is that preexisting (albeit vague and contested) boundaries and options exist; opportunities for invention are not generous

The Construction of Verification Models for Embedded Systems

The usefulness of verification hinges on the quality of the verification model. Verification is useful if it increases our confidence that an artefact bahaves as expected. As modelling inherently contains non-formal elements, the qualityof models cannot be captured by purely formal means. Still, we argue that modelling is not an act of irrationalism and unpredictable geniality, but follows rational arguments, that often remain implicit. In this paper we try to identify the tacit rationalism in the model construction as performed by most people doing modelling for verification. By explicating the different phases, arguments, and design decisions in the model construction, we try to develop guidelines that help to improve the process of model construction and the quality of models

Avoiding Wireheading with Value Reinforcement Learning

How can we design good goals for arbitrarily intelligent agents? Reinforcement learning (RL) is a natural approach. Unfortunately, RL does not work well for generally intelligent agents, as RL agents are incentivised to shortcut the reward sensor for maximum reward -- the so-called wireheading problem. In this paper we suggest an alternative to RL called value reinforcement learning (VRL). In VRL, agents use the reward signal to learn a utility function. The VRL setup allows us to remove the incentive to wirehead by placing a constraint on the agent's actions. The constraint is defined in terms of the agent's belief distributions, and does not require an explicit specification of which actions constitute wireheading.Comment: Artificial General Intelligence (AGI) 201

Co-Constructing Writing Knowledge: Students’ Collaborative Talk Across Contexts

Although compositionists recognize that student talk plays an important role in learning to write, there is limited understanding of how students use conversational moves to collaboratively build knowledge about writing across contexts. This article reports on a study of focus group conversations involving first-year students in a cohort program. Our analysis identified two patterns of group conversation among students: “co-telling” and “co-constructing,” with the latter leading to more complex writing knowledge. We also used Beaufort’s domains of writing knowledge to examine how co-constructing conversations supported students in abstracting knowledge beyond a single classroom context and in negotiating local constraints. Our findings suggest that co-constructing is a valuable process that invites students to do the necessary work of remaking their knowledge for local use. Ultimately, our analysis of the role of student conversation in the construction of writing knowledge contributes to our understanding of the myriad activities that surround transfer of learning

Prototype system for supporting the incremental modelling of vague geometric configurations

In this paper the need for Intelligent Computer Aided Design (Int.CAD) to jointly support design and learning assistance is introduced. The paper focuses on presenting and exploring the possibility of realizing learning assistance in Int.CAD by introducing a new concept called Shared Learning. Shared Learning is proposed to empower CAD tools with more useful learning capabilities than that currently available and thereby provide a stronger interaction of learning between a designer and a computer. Controlled computational learning is proposed as a means whereby the Shared Learning concept can be realized. The viability of this new concept is explored by using a system called PERSPECT. PERSPECT is a preliminary numerical design tool aimed at supporting the effective utilization of numerical experiential knowledge in design. After a detailed discussion of PERSPECT's numerical design support, the paper presents the results of an evaluation that focuses on PERSPECT's implementation of controlled computational learning and ability to support a designer's need to learn. The paper then discusses PERSPECT's potential as a tool for supporting the Shared Learning concept by explaining how a designer and PERSPECT can jointly learn. There is still much work to be done before the full potential of Shared Learning can be realized. However, the authors do believe that the concept of Shared Learning may hold the key to truly empowering learning in Int.CAD

The variable containment problem

The essentially free variables of a term $t$ in some $\lambda$-calculus, FV $_{\beta}(t)$, form the set ($x$ $_{\mid}^{\mid}$ $\forall u.t=_{\beta}u\Rightarrow x$ $\epsilon$ FV$(u)$}. This set is significant once we consider equivalence classes of $\lambda$-terms rather than $\lambda$-terms themselves, as for instance in higher-order rewriting. An important problem for (generalised) higher-order rewrite systems is the variable containment problem: given two terms $t$ and $u$, do we have for all substitutions $\theta$ and contexts $C$[] that FV$_{\beta}(C[t]^{\theta}) \supseteq$ FV$_{\beta}(C[u^{\theta}])$? This property is important when we want to consider $t \to u$ as a rewrite rule and keep $n$-step rewriting decidable. Variable containment is in general not implied by FV $_{\beta} (t)\supseteq$ FV$_{\beta}(u)$. We give a decision procedure for the variable containment problem of the second-order fragment of $\lambda^{\to}$. For full $\lambda^{\to}$ we show the equivalence of variable containment to an open problem in the theory of PCF; this equivalence also shows that the problem is decidable in the third-order case