<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">De Mol, Liesbeth</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">On the complex behavior of simple tag systems  An experimental approach</style></title><secondary-title><style face="normal" font="default" size="100%">Theoretical Computer Science</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">412</style></volume><pages><style face="normal" font="default" size="100%">97–112</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;It is a well-know fact that apparently simple systems can give rise to complex behavior. But why exactly does a given system behave in a complex manner? There are two main approaches to tackle this and other related questions. One can take on a more theoretical approach or start from a more experimental study of the behavior of such systems with the help of the computer. In this paper, the experimental approach will be applied to very small tag systems. After a discussion of some of the main theoretical results on tag systems, several results from a computer-assisted and experimental study on tag systems will be analyzed. Special attention will be given to the well-known example Post provided and studied with only 2 symbols and a deletion number v = 3. These results will be combined with some theoretical results on tag systems in order to gain more insight into the computational power of simple tag systems.&lt;/p&gt;</style></abstract></record></records></xml>