@inproceedings{86d2c351515f4271b003db2929736319,
title = "Impossibility results for the equational theory of timed CCS",
abstract = "We study the equational theory of Timed CCS as proposed by Wang Yi in CONCUR{\textquoteright}90. Common to Wang Yi{\textquoteright}s paper, we particularly focus on a class of linearly-ordered time domains exemplified by the positive real or rational numbers. We show that, even when the set of basic actions is a singleton, there are parallel Timed CCS processes that do not have any sequential equivalent and thus improve on the Gap Theorem for Timed CCS presented by Godskesen and Larsen in FSTTCS{\textquoteright}92. Furthermore, we show that timed bisimilarity is not finitely based both for single-sorted and two-sorted presentations of Timed CCS. We further strengthen this result by showing that, unlike in some other process algebras, adding the untimed or the timed left-merge operator to the syntax and semantics of Timed CCS does not solve the axiomatizability problem.",
author = "L. Aceto and A. Ing{\'o}lfsd{\'o}ttir and M. Mousavi",
year = "2007",
doi = "10.1007/978-3-540-73859-6\_6",
language = "English",
isbn = "978-3-540-73857-2",
series = "Lecture Notes in Computer Science",
publisher = "Springer",
pages = "80--95",
editor = "T. Mossakowski and U. Montanari and M. Haveraaen",
booktitle = "Proceedings 2nd Conference on Algebra and Coalgebra in Computer Science (CALCO 2007) 20-24 August 2007, Bergen, Norway",
address = "Germany",
note = "conference; CALCO 2007, Bergen, Norway; 2007-08-20; 2007-08-24 ; Conference date: 20-08-2007 Through 24-08-2007",
}