This article constitutes a contribution to an analysis of the notion of variable. Whithin the framework of Combinatory Logic as a formalism without bound variables, the Logic of Determination of Objects (LDO) provides an explanation for the necessary distinction between “whatever, any” and “indeterminate, indefinite” used by the introduction and elimination rules of quantifiers in Natural Deduc...

Access control is key to limiting the actions of users in an application and attribute-based policy languages such as XACML allow to express a wide range of access rules. As these policy languages become more widely used, policies grow both in size and complexity. Modularity and reuse are key to specifying and managing such policies effectively. Ideally, complex or domain-specific policy patter...

The class of Basic Feasible Functionals BFF$_2$ is the type-2 counterpart FP type-1 functions computable in polynomial time. Several characterizations have been suggested literature, but none these present a programming language with type system guaranteeing this complexity bound. We give characterization based on an imperative oracle calls using tier-based whose inference decidable. Such shoul...

For representing high level knowledge, such as the mathematical knowledge used in interactive theorem provers and veriication systems, it is desirable to extend Prolog's concept of data object. A basic reason is that Prolog data objects | Herbrand objects | are terms of a minimal object language, which does not include its own object variables, or quantiication over those variables. Qu-Prolog (...

The approach to reasoning about structural operational semantics style specifications supported by the Abella system is discussed. This approach uses λ-tree syntax to treat object language binding and encodes binding related properties in generic judgments. Further, object language specifications are embedded directly into the reasoning framework through recursive definitions. The treatment of ...

Existing libraries and languages for nite domain constraint programming usually have depth-rst search (with branch and bound) built-in as the only search algorithm. Exceptions are the languages claire and Oz, which support the programming of diierent search algorithms through special purpose programming language constructs. The goal of this work is to make abstractions for programming search al...

There are many ways of representing language as a physical organ that are made available by the human and the natural sciences. Shaping our understanding, such representations generate views of language that are simultaneously abstract and physical. These views are mediated both by theoretical accounts and imaging tools which both implicitly and explicitly localize and imagine language as an in...

In this paper, we show that in each nite dimensional Hilbert space, a frame of subspaces is an ultra Bessel sequence of subspaces. We also show that every frame of subspaces in a nite dimensional Hilbert space has frameness bound.