Recently discovered tetraquark and pentaquark structures have renewed interest in multiquark states. In the spirit of these results, masses postulated hexaquark using a first-order mass formula are determined. The hexaquarks model is applied to ΩΩ, ΩcccΩccc, ΩbbbΩbbb dibaryon suggests that 3.53, 9.78, 28.8 GeV/c2, respectively.

In an earlier paper, the author used derivatives to construct a deterministic automaton recognizing the language defined by an ω-regular expression. The construction was related to a determinization method invented by Safra. This paper describes a new construction, inspired by Piterman’s improvement to Safra’s method. It produces an automaton with fewer states. In addition, the presentation and...

We follow a connection between tight determinisation and complementation and establish a complementation procedure from transition-labelled parity automata to transition-labelled nondeterministic Büchi automata. We prove it to be tight up to an O(n) factor, where n is the size of the nondeterministic parity automaton. This factor does not depend on the number of priorities.

I was supposed to deliver one of the speeches at Wolfgang Thomas’s retirement ceremony. Wolfgang had called me on the phone earlier and posed some questions about temporal logic, but I hadn’t had good answers at the time. What I decided to do at the ceremony was to take up the conversation again and show how it could have evolved if only I had put more effort into answering his questions. Here ...

This paper reports extensions to the GOAL tool that enable it to become a research tool for omega automata and temporal logic. The extensions include an expanded collection of translation, simplification, and complementation algorithms, a command-line mode which makes GOAL functions accessible by programs, and utility functions for such common tasks as file format conversion, random formulae ge...