Two-level Grammar Research Articles

A two-level grammar of the reduction processes of French complex terms in discourse

The aim of this paper is to offer an outline of a descriptive grammar — as yet unfinished — of two reduction processes, namely elliptic anaphor and lexical elision, which delete constituents of reiterated complex terms in French LSP texts. After an examination of these reduction processes and the term variants they generate, the paper presents the main building blocks of the grammar. The architecture of these building blocks, i.e. of the deep and surface structure rules which constitute the two levels of the grammar, is derived from the structural and semantic properties of French complex terms. The ordering of the rules in the grammar, on the other hand, is based on characteristics of elliptic anaphor and lexical elision as well as on properties of the term variants produced by these context-conditioned transformations.

A quality‐of‐service‐based framework for creating distributed heterogeneous software components

AbstractComponent‐based software development offers a promising solution for taming the complexity found in today's distributed applications. Today's and future distributed software systems will certainly require combining heterogeneous software components that are geographically dispersed. For the successful deployment of such a software system, it is necessary that its realization, based on assembling heterogeneous components, not only meets the functional requirements, but also satisfies the non‐functional criteria such as the desired quality of service (QoS). In this paper, a framework based on the notions of a meta‐component model, a generative domain model and QoS parameters is described. A formal specification based on two‐level grammar is used to represent these notions in a tightly integrated way so that QoS becomes a part of the generative domain model. A simple case study is described in the context of this framework. Copyright © 2002 John Wiley & Sons, Ltd.

Dynamic semantic specification by two-level grammars for a block structured language with subroutine parameters

This paper presents the application of a formal description language -- Van Wijngaarden Two-Level grammar -- to define the dynamic semantics of a block structured language consisting of several types of parameter passing mechanisms. We will show, in a fairly understandable, concise and clear fashion, that the metalinguistic formalism of Two-Level grammar is a fine descriptive device for this purpose.

Two-level Grammar as a Functional Programming Language

Two-level Grammar as a Functional Programming Language

Towards a programming language based on the notion of two-level grammar: Jan Maluszynski: Software Systems Research Center, Linkoeping Institute of Technology, Linkoeping, June 1982

Towards a programming language based on the notion of two-level grammar: Jan Maluszynski: Software Systems Research Center, Linkoeping Institute of Technology, Linkoeping, June 1982

Two-level grammar as an implementable metalanguage for axiomatic semantics

Two-level grammars can define the syntax and the operational semantics of programming languages and these definitions are directly executable by interpretation. In this paper it is shown that axiomatic semantics can also be defined using a two-level grammar with the result being a partially automatic program verification system accomplished within the framework of a language definition. These results imply that a programming language can be defined operationally and axiomatically together in complementary definitions as advocated by Hoare and Lauer. Because two-level grammars are executable, these complementary definitions accomplish a system for interpreting and verifying programs.

How to produce all sentences from a two-level grammar

Two-level grammars are very readable formalisms for generating Chomsky Type 0 languages. Teaching and understanding them is greatly aided by the presence of a sentence generator. This paper shows how a usable sentence generator can be constructed. A working program is available from the author.

Formal syntax methods for natural language

This paper describes on-going research into the applications of some techniques normally used to formally specify and analyze the context-sensitive syntax of programming languages to the specification and analysis of the syntax of a natural language, namely English. The specific formal methods presently being investigated are two-level grammar (2LG) and the Vienna Definition Language (VDL). A preliminary subset of English has been established consisting of fifteen basic sentence patterns. 2LG and VDL specifications are given for one of these sentence types and the syntactic analysis of an English sentence using each of the two specifications is illustrated through an example.

Organization and learnability in computer languages

A number of “guiding principles” have been put forward for the design of easily-learnt languages, but little attention has been given to the overall structure or organization of the language. We propose a new principle, that of consistency between language rules, and show that this “organizing” principle is strongly related to the concepts of hyper-rules and meta-rules in van Wijngaarden's two-level grammar. We report an experiment comparing four separate namesets for a subset of a word-processing language, which demonstrates that the organization of the lexical rules is more important than the match between any one command and its name; performance with the nameset in which two conflicting organization principles were at work was much poorer than with consistent namesets whose organizing principles could readily be perceived by subjects.

Towards a programming language based on the notion of two-level grammar

This paper deals with the problem of computing relations from their abstract non-algorithmic specifications. The formalism under consideration is that of two-level grammars, introduced originally for defining languages. In this formalism the intuitions behind the formal definition can be directly expressed by the grammatical rules, which may have a form close to the statements of natural language. A notion of the relation specified by a two-level grammar is introduced and computability of such relations is discussed. For a class of two-level grammars, called the transparent grammars, an algorithm is outlined for computing the relations specified by the grammars of this class. The transparent grammars turn out to be a generalization of the formalism of Horn clauses, and the algorithm is based on unification. The language generated by a two-level grammar can be used as an additional tool for controlling computations. A transparent two-level grammar can be considered as a non-algorithmic program specifying an input/output relation. The computational algorithm defines an operational semantics of such programs.

Two-level meta-controlled substitution grammars

A language-generating mechanism, inspired on the two-level van Wijngaarden syntax for Algol 68, is considered. Its language generating properties are studied and compared to those of well-known classical systems and grammars. The new mechanism is called a 2 MSG, for "two-level metacontrolled substitution grammar."