Different types of subregular expressions are studied. Each type is obtained by either omitting one of the regular operations or replacing it by complementation or intersection. For uniformity and in order to allow non-trivial languages to be expressed, the set of literals is a finite set of words instead of letters. The power and limitations as well as relations with each other are considered, which is often done in terms of unary languages. Characterizations of some of the language families are obtained. A finite hierarchy is shown that reveals that the operation complementation is generally stronger than intersection. Furthermore, we investigate the closures of language families described by regular expressions with omitted operation under that operation. While it is known that in case of union this closure captures all regular languages, for the cases of concatenation and star incomparability results are obtained with the corresponding language families where the operation is replaced by complementation.
DOI : 10.1051/ita/2018014
Mots-clés : Regular expressions, concatenation-free languages, star-free languages, union-free languages, expressive capacity, characterizations, closure properties, subregular hierarchy
@article{ITA_2018__52_2-3-4_201_0, author = {Kutrib, Martin and Wendlandt, Matthias}, editor = {Bordihn, Henning and Nagy, Benedek and Vaszil, Gy\"orgy}, title = {Expressive capacity of subregular expressions}, journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications}, pages = {201--218}, publisher = {EDP-Sciences}, volume = {52}, number = {2-3-4}, year = {2018}, doi = {10.1051/ita/2018014}, mrnumber = {3915309}, zbl = {1475.68162}, language = {en}, url = {http://www.numdam.org/articles/10.1051/ita/2018014/} }
TY - JOUR AU - Kutrib, Martin AU - Wendlandt, Matthias ED - Bordihn, Henning ED - Nagy, Benedek ED - Vaszil, György TI - Expressive capacity of subregular expressions JO - RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications PY - 2018 SP - 201 EP - 218 VL - 52 IS - 2-3-4 PB - EDP-Sciences UR - http://www.numdam.org/articles/10.1051/ita/2018014/ DO - 10.1051/ita/2018014 LA - en ID - ITA_2018__52_2-3-4_201_0 ER -
%0 Journal Article %A Kutrib, Martin %A Wendlandt, Matthias %E Bordihn, Henning %E Nagy, Benedek %E Vaszil, György %T Expressive capacity of subregular expressions %J RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications %D 2018 %P 201-218 %V 52 %N 2-3-4 %I EDP-Sciences %U http://www.numdam.org/articles/10.1051/ita/2018014/ %R 10.1051/ita/2018014 %G en %F ITA_2018__52_2-3-4_201_0
Kutrib, Martin; Wendlandt, Matthias. Expressive capacity of subregular expressions. RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 52 (2018) no. 2-3-4, pp. 201-218. doi : 10.1051/ita/2018014. http://www.numdam.org/articles/10.1051/ita/2018014/
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