Derivatives of Regular Expressions
- 1 October 1964
- journal article
- Published by Association for Computing Machinery (ACM) in Journal of the ACM
- Vol. 11 (4) , 481-494
- https://doi.org/10.1145/321239.321249
Abstract
Kleene's regular expressions, which can be used for describing sequential circuits, were defined using three operators (union, concatenation and iterate) on sets of sequences. Word descriptions of problems can be more easily put in the regular expression language if the language is enriched by the inclusion of other logical operations. However, il~ the problem of converting the regular expression description to a state diagram, the exist- ing methods either cannot handle expressions with additional operators, or are made quite complicated by the presence of such operators. In this paper the notion of a derivative of a regular expression is introduced atld the properties of derivatives are discussed. This leads, in a very natural way, to the construction of a state diagram from a regular expression containing any number of logical operators.Keywords
This publication has 5 references indexed in Scilit:
- Design of Sequential Machines from Their Regular ExpressionsJournal of the ACM, 1961
- Finite Automata and Their Decision ProblemsIBM Journal of Research and Development, 1959
- Sequential FunctionsJournal of the ACM, 1958
- Realization of Events by Logical NetsJournal of the ACM, 1958
- A method for synthesizing sequential circuitsBell System Technical Journal, 1955