k-p-Infix codes and semaphore codes Original Research Article

In this paper we introduce the concepts of k-p-infix codes, n-k-ps-infix languages, n-k-infix-outfix codes, and n-k-prefix-suffix languages, which are natural generalizations of our previous work on k-prefix codes, k-infix codes and so on. We obtain several properties of k-p-infix codes and semaphore codes. The relations and hierarchies of k-p-infix codes, n-k-ps-languages, and n-k-prefix-suffix languages, and their operations of these classes of languages are also investigated.