%0 Conference Proceedings
%T Tag Systems and the Complexity of Simple Programs
%+ Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology  [Zürich] (ETH Zürich)
%+ California Institute of Technology (CALTECH)
%A Neary, Turlough
%A Woods, Damien
%Z Part 1: Invited Papers
%< avec comité de lecture
%( Lecture Notes in Computer Science
%B 21st Workshop on Cellular Automata and Discrete Complex Systems (AUTOMATA)
%C Turku, Finland
%Y Jarkko Kari
%I Springer
%3 Cellular Automata and Discrete Complex Systems
%V LNCS-9099
%P 11-16
%8 2015-06-08
%D 2015
%R 10.1007/978-3-662-47221-7_2
%Z Computer Science [cs]Conference papers
%X In this mini-survey we discuss time complexity and program size results for universal Turing machines, tag systems, cellular automata, and other simple models of computation. We discuss results that show that many of the simplest known models of computation including the smallest known universal Turing machines and the elementary cellular automaton Rule 110 are efficient simulators of Turing machines. We also recall a recent result where the halting problem for tag systems with only 2 symbols (the minimum possible) is proved undecidable. This result has already yielded applications including a significant improvement on previous undecidability bounds for the Post correspondence problem and the matrix mortality problem.
%G English
%Z TC 1
%Z WG 1.5
%2 https://inria.hal.science/hal-01442479/document
%2 https://inria.hal.science/hal-01442479/file/338243_1_En_2_Chapter.pdf
%L hal-01442479
%U https://inria.hal.science/hal-01442479
%~ IFIP-LNCS
%~ IFIP
%~ IFIP-TC
%~ IFIP-TC1
%~ IFIP-LNCS-9099
%~ IFIP-WG1-5
%~ IFIP-AUTOMATA