The power of H systems : does representation matter ?

Splicing rules of the form (u; v; w; x) are usually represented as strings of the form u#v$w#x. The eeect of splicing with rules from several families of languages has been determined in the literature. We investigate whether the results about splicing systems obtained in this way are indeed properties of the splicing system and not of the speciic string representation of the rules. We study in detail single and iterated splicing systems, by considering the alternative string representation u#w$v#x, and indeed obtain the same classiications as for the standard representation. We brieey discuss some related representations.