We present a method to support the gradual evolution of secure scripts by formalizing an extension of the simply-typed lambda calculus that provides information flow constructs. These constructs allow initially insecure programs to evolve via targeted refactoring and to provide dynamic information flow guarantees via casts, as well as static information flow guarantees via labeled types.

Static verification traditionally produces yes/no answers. It either provides a proof that a piece of code meets a property, or a counterexample showing that the property can be violated. Hence, the progress of static verification is hard to measure. Unlike in testing, where coverage metrics can be used to track progress, static verification does not provide any intermediate result until the pr...

The current study investigated whether gradually reducing the frequency of aversive stimuli during extinction can prevent the return of fear. Thirty-one participants of a three-stage procedure (acquisition, extinction and a reinstatement test on day 2) were randomly assigned to a standard extinction (SE) and gradual extinction (GE) procedure. The two groups differed only in the extinction proce...

In this paper, we introduce a new fuzzy metric based on gradual numbers. Firstly, the concept of gradual metric spaces is introduced. And then, basic topological concepts in gradual metric spaces are presented and their properties are investigated. Mathematics Subject Classification: 54E35, 03E72

Mining emerging patterns aims at contrasting data sets and identifying itemsets that characterise a data set by contrast to a reference data set, so as to capture and highlight their differences. This paper considers the case of emerging gradual patterns, to extract discriminant attribute co-variations. It discusses the specific features of these gradual patterns and proposes to transpose an ef...

We present gradual liquid type inference, a novel combination of refinement types with gradual refinements that range over a finite set of SMT-decidable predicates. This finiteness restriction allows for an algorithmic inference procedure where all possibly valid interpretations of a gradual refinement are exhaustively checked. Thanks to exhaustive searching we can detect the safe concretizatio...

William Walker is professor of international relations at the University of St. Andrews in Scotland. He is the co-author with David Albright and Frans Berkhout of SIPRI’s Plutonium and Highly Enriched Uranium: World Inventories, Capabilities and Policies (forthcoming, 1996). There have been many recent cases of states reversing course. Russia has embraced capitalism and democracy, China has thr...

What is the impact of surprise and anticipated policy changes when agents form expectations using adaptive learning rather than rational expectations? We examine this issue using the standard stochastic real business cycle model with lump-sum taxes. Agents combine knowledge about future policy with econometric forecasts of future wages and interest rates. Dynamics under learning can have large ...

We have ∀X.A′ ≺ ∀X.B, so A′ ≺ B. Also, we have Σ ` V X : A′, so the RHS has type B = A. • Case (V : A′ p =⇒ ∀X.B) X 7−→ V : A′ p =⇒ B : We have A′ ≺ ∀X.B, so A′ ≺ B. Thus, the RHS has type B = A. • Case V : ∀X.A′ p =⇒ B 7−→ (V ?) : A′[X:=?] p =⇒ B : We have ∀X.A′ ≺ B, so A′[X:=?] ≺ B by Lemma 1. Thus, the RHS has type B. Definition 3. Well-typed contexts, written Σ B E : B ⇒ A, are defined in t...

Siek and Taha [2006] coined the term gradual typing to describe a theory for integrating static and dynamic typing within a single language that 1) puts the programmer in control of which regions of code are statically or dynamically typed and 2) enables the gradual evolution of code between the two typing disciplines. Since 2006, the term gradual typing has become quite popular but its meaning...