A language theoretic analysis of combings
نویسنده
چکیده
A group is combable if it can be represented by a language of words satisfying a fellow traveller property; an automatic group has a synchronous combing which is a regular language. This paper gives a systematic analysis of the properties of groups with combings in various formal language classes, and of the closure properties of the associated classes of groups. It generalises previous work, in particular of Epstein et al. and Bridson and Gilman.
منابع مشابه
A Language Theoretic Analysis of CombingsSarah
A group is combable if it can be represented by a language of words satisfying a fellow traveller property; an automatic group has a synchronous combing which is a regular language. This paper gives a systematic analysis of the properties of groups with combings in various formal language families, and of the closure properties of the associated families of groups; it explores the relationship ...
متن کاملA Remark about Combings of Groups
In the last several years a remarkable interplay between geometry, group theory, and the theory of formal languages has led to developments including the introduction of automatic groups [Ep+], hyperbolic groups [Gro], and geometric and language-theoretic characterizations of finitely generated virtually free groups [MS1] [MS2]. A prime example of such interplay is the study of combings, which ...
متن کاملCombings of Groups and the Grammar of Reparameterization
A new construction of combings is used to distinguish between several previously indistinguishable classes of groups associated to the theory of automatic groups and non-positive curvature in group theory. We construct synchronously bounded combings for a class of groups that are neither bicombable nor automatic. The linguistic complexity of these combings is analysed: in many cases the languag...
متن کاملA Note on the Grammar Of Combings
Explicit constructions are given to illustrate the loss of control that ensues when one replaces the regular languages of automatic group theory with larger families of languages. The results of [2] show that one can distinguish between various classes of combable groups by analyzing the grammatical complexity of the combings that the groups admit. That work clarifies the boundaries of automati...
متن کاملThe Effect of Grammar vs. Vocabulary Pre-teaching on EFL Learners’ Reading Comprehension: A Schema-Theoretic View of Reading
This study was designed to investigate the effect of grammar and vocabulary pre-teaching, as two types of pre-reading activities, on the Iranian EFL learners’ reading comprehension from a schema–theoretic perspective. The sample consisted of 90 female students studying at pre-university centers of Isfahan. The subjects were randomly divided into three equal-in-number groups. They participated ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1997