James W. Thatcher

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Many of the important concepts and results of conventional finite automata theory are developed for a generalization in which finite algebras take the place of finite automata. The standard closure theorems are proved for the class of sets “recognizable” by finite algebras, and a generalization of Kleene's regularity theory is presented. The theorems of the(More)
Many apparently divergent approaches to specifying formal semantics of programming languages are applications of initial algebra semantics. In this paper an overview of initial algebra semantics is provided. The major technical feature is an initial continuous algebra which permits unified algebraic treatment of iterative and recursive semantic features in(More)
This paper extends our earlier work on abstract data types by providing an algebraic treatment of parametrized data types (e.g., sets-of-(), stacks-of-(), etc.), as well as answering a number of questions on the power and limitations of algebraic specification techniques. In brief: we investigate the “hidden function” problem (the need to(More)
In this paper NT study the semantics of the parameter passing mechanism in algebraic qwcilication Ianguagcs. ;Ilore precisely. this problem is studied for parameterizcd data types and ptmmeterized qxcilkations. The given results include the extension of the model functor (which ih uwfuI for corrwtness proofs) and the semantic properties of the result ot(More)
The objective of this work is to expand the study of generalized finite automata theory by introducing generalized finite state mappings (finite state mappings of trees). In the process, we hope to provide an algebraic framework in which to study formalizations of transformations (in the sense that linguists use the term) and translations of natural and(More)
M. King J. W. Thatcher P. M. Bronstad R. Easton The case for ensuring that Web sites are usable by people with disabilities is strong in light of the World Wide Web’s ubiquity as an essential customer interface for most organizations, the considerable disposable income of people with disabilities, and a growing number of accessibility regulations being(More)