We prove that for every regular comma-free code there exists a maximal comma-free code containing it which is still regular and, moreover, we can effectively locate such a completion. In particular, we can decide whether a given regular comma-free code is maximal.

Adámek and Sousa recently solved the problem of characterizing the subcategories K of a locally λ-presentable category C which are λ-orthogonal in C, using their concept of Kλ-pure morphism. We strenghten the latter definition, in order to obtain a characterization of the classes defined by orthogonality with respect to λ-presentable morphisms (where f :A B is called λ-presentable if it is a λ-...

We propose an unfolding semantics for graph transformation systems in the double-pushout (DPO) approach. Mimicking Winskel’s construction for Petri nets, a graph grammar is unfolded into an acyclic branching structure, that is itself a (nondeterministic occurrence) graph grammar describing all the possible computations of the original grammar. The unfolding can be abstracted naturally to a prim...

The Chinese comma signals the boundary of discourse units and also anchors discourse relations between adjacent text spans. In this work, we propose a discourse structureoriented classification of the comma that can be automatically extracted from the Chinese Treebank based on syntactic patterns. We then experimented with two supervised learning methods that automatically disambiguate the Chine...

The two primary objectives of this paper are: (a) to demonstrate how Comma, a business modeling methodology based on commitments, can be applied in healthcare process modeling, and (b) to evaluate the effectiveness of such an approach in producing healthcare process models. We apply the Comma approach on a breast cancer diagnosis process adapted from an HHS committee report, and presents the re...

This paper studies conditions under which the operation of parallel insertion can be reversed by parallel deletion, i.e., when does the equality (L1 ⇐ L2) ⇒ L2 = L1 hold for languages L1 and L2. We obtain a complete characterization of the solutions in the special case when both languages involved are singleton words. We also define comma codes, a family of codes with the property that, if L2 i...

This paper reports on initial experiments with automatic comma recovery in legal texts. In deciding whether to insert a comma or not, we propose to use the value of the probability of a bigram of two words without a comma and a trigram of the words with the comma. The probability is determined by the language model trained on sentences with commas labeled as separate words. In the training data...

A significant sector of coding theory is that of comma-free coding; that is, codes which can be received without the need of a letter used for word separation. The major difficulty is in finding bounds on the maximum number of comma-free words which can inhabit a dictionary. We introduce a new class called a self-reflective comma-free dictionary and prove a series of bounds on the size of such ...

The definition of comma-free codes is extended to be more comprehensive and include codes with variable length codewords and codes with an unlimited number of codewords. Finite state recognizers are used to represent commafree codes in a compact form, making available the well established methods of manipulating and analysing finite state models. An efficient algorithm is presented to test the ...