08.01.2013 Views

LNCS 2950 - Aspects of Molecular Computing (Frontmatter Pages)

LNCS 2950 - Aspects of Molecular Computing (Frontmatter Pages)

LNCS 2950 - Aspects of Molecular Computing (Frontmatter Pages)

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

On Some Classes <strong>of</strong> Splicing Languages ⋆<br />

Rodica Ceterchi 1 , Carlos Martín-Vide 2 , and K.G. Subramanian 3<br />

1 Faculty <strong>of</strong> Mathematics, University <strong>of</strong> Bucharest<br />

14, Academiei st., 70109 Bucharest, Romania<br />

rc@funinf.math.unibuc.ro, rc@fll.urv.es<br />

2 Research Group in Mathematical Linguistics<br />

Rovira i Virgili University<br />

Pl. Imperial Tàrraco 1, 43005 Tarragona, Spain<br />

cmv@astor.urv.es<br />

3 Department <strong>of</strong> Mathematics<br />

Madras Christian College<br />

Tambaram, Chennai 600059, India<br />

kgsmani@vsnl.net<br />

Abstract. We introduce some classes <strong>of</strong> splicing languages generated<br />

with simple and semi-simple splicing rules, in both, the linear and circular<br />

cases. We investigate some <strong>of</strong> their properties.<br />

1 Introduction<br />

The operation <strong>of</strong> splicing was introduced as a generative mechanism in formal<br />

language theory by Tom Head in [9], and lays at the foundation <strong>of</strong> the field <strong>of</strong><br />

DNA based computing (see [11] and [14].)<br />

We are concerned in this paper with some classes <strong>of</strong> languages which arise<br />

when considering very simple types <strong>of</strong> splicing rules. Our main inspiration is the<br />

study <strong>of</strong> [12], where the notion <strong>of</strong> simple H system and the associated notion <strong>of</strong><br />

simple splicing languages have been introduced.<br />

A simple splicing rule is a rule <strong>of</strong> the form (a, 1; a, 1) with a ∈ A asymbol<br />

called marker. More precisely, we will call such a rule a (1, 3)-simple splicing<br />

rule, since the marker a appears on the 1 and 3 positions <strong>of</strong> the splicing rule,<br />

and since one can conceive <strong>of</strong> (i, j)-simple splicing rules for all pairs (i, j) with<br />

i =1, 2, j =3, 4. We denote by SH(i, j) the class <strong>of</strong> languages generated by<br />

simple splicing rules <strong>of</strong> type (i, j). The paper [12] focuses basically on the study<br />

<strong>of</strong> the SH(1, 3) class (which is equal to the SH(2, 4) class and is denoted by SH).<br />

Only towards the end <strong>of</strong> the paper the authors <strong>of</strong> [12] show that there are three<br />

such distinct and incomparable classes, SH = SH(1, 3) = SH(2, 4), SH(2, 3)<br />

and SH(1, 4), <strong>of</strong> (linear) simple splicing languages. They infer that most <strong>of</strong> the<br />

results proven for the SH class will hold also for the other classes, and point out<br />

towards studying one-sided splicing rules <strong>of</strong> radius at most k: rules(u1, 1; u3, 1)<br />

⋆ This work was possible thanks to the grants SAB2000-0145, and SAB2001-0007,<br />

from the Secretaría de Estado de Educación y Universidades, Spanish Ministry for<br />

Education, Culture and Sport.<br />

N. Jonoska et al. (Eds.): <strong>Molecular</strong> <strong>Computing</strong> (Head Festschrift), <strong>LNCS</strong> <strong>2950</strong>, pp. 84–105, 2004.<br />

c○ Springer-Verlag Berlin Heidelberg 2004

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!