Arithmetic AN codes are useful for error correction in both arithmetic operations and digital data transmission. This paper presents a theoretical approach to a new class of nonbinary arithmetic AN codes using symmetric R-ary expressions and Lee-type arithmetic distance.

This correspondence describes an efficient string pattern matching machine to locate all occurrences of any of a finite number of keywords and phrases in an arbitrary text string. Some conditions are defined on the states of the machine in order to improve the speed and size of the machine by Aho and Corasick [1]. The pattern matching algorithm is partitioned into various cases by combining these conditions. Finally, the correspondence illustrates the proposed approach by applying it to the analysis of the machines for a simple search.

This paper presents a practical method for constructing a more compact matrix structure of the precedence information used in a new weak precedence parsing. The parsing algorithm differs from the conventional weak precedence algorithm in that the precedence relation .> signals a sequence of reduce actions, not just one. The method can be used for any weak precedence grammars without degrading the good error detection capability of the traditional weak precedence parsers. It is shown by the empirical results that the obtained matrices are the very reasonable size and that the presented parsing algorithm is very efficient.