Formal language

About: Formal language is a research topic. Over the lifetime, 5763 publications have been published within this topic receiving 154114 citations.

Automatic generation of language-based tools

Abstract: Many tools can be automatically derived from formal language definitions, such as compilers/interpreters, editors, analyzers, visualizers/animators, etc. Some examples of language-based tools generated automatically by the LISA system are described in the paper. In addition the specification of an algorithm animator and program visualizer, Alma, generated from an extended LISA input-grammar is discussed; LISA principles and code are reused in Alma implementation.

Higher-Order Abstract Syntax with Induction in Isabelle/HOL: Formalizing the pi-Calculus and Mechanizing the Theory of Contexts

Abstract: Higher-order abstract syntax is a natural way to formalize programming languages with binders, like the π-calculus, because α-conversion, instantiations and capture avoidance are delegated to the meta-level of the provers, making tedious substitutions superfluous. However, such formalizations usually lack structural induction, which makes syntax-analysis impossible. Moreover, when applied in logical frameworks with object-logics, like Isabelle/HOL or standard extensions of Coq, exotic terms can be defined, for which important syntactic properties become invalid. The paper presents a formalization of the π-calculus in Isabelle/HOL, using well-formedness predicates which both eliminate exotic terms and yield structural induction. These induction-principles are then used to derive the Theory of Contexts fully within the mechanization.

Defaults and revision in structured theories

Abstract: Starting from a logic which specifies how to make deductions from a set of sentences (a flat theory), a way to generalize this to a partially ordered bag of sentences (a structured theory) is given. The partial order is used to resolve conflicts. If phi occurs below psi , then psi is accepted only insofar as it does not conflict with phi . The study starts with a language L, a set of interpretations M and a satisfaction relation. The key idea is to define, for each structured theory, a preorder on interpretations. Models of the structured theory are defined to be maximal interpretations in the ordering. A revision operator that takes a structured theory and a sentence and returns a structured theory is defined. The consequence relation has the properties of weak monotonicity, weak cut, and weak reflexivity with respect to this operator, but fails their strong counterparts. >

Language Issues for Cognitive Radio

Abstract: This paper discusses various aspects of formal languages in the context of cognitive radio. A bottom up approach is taken in which an example of a specification of a feature of cognitive radio in a selected language is shown, followed by an example of a feature that cannot be expressed in the language and the identification of a capability that needs to be added to the language in order to cover the identified gap in the expressiveness. Following this pattern, we start with a language based on description logics and add the capability of expressing rules, then functions, and finally behavioral aspects. The running example used in this paper - conveying the description of a component to be synthesized by another radio - covers two major aspects of a cognitive radio: an ability to express own capabilities and an ability to interoperate with other cognitive radios.