All Outputs (2)

Reachability problems in quaternion matrix and rotation semigroups (2008)
Journal Article
Bell. (2008). Reachability problems in quaternion matrix and rotation semigroups. Information and Computation, 1353 - 1361. https://doi.org/10.1016/j.ic.2008.06.004

We examine computational problems on quaternion matrix and rotation semigroups. It is shown that in the ultimate case of quaternion matrices, in which multiplication is still associative, most of the decision problems for matrix semigroups are undeci... Read More about Reachability problems in quaternion matrix and rotation semigroups.

On undecidability bounds for matrix decision problems (2008)
Journal Article
Bell. (2008). On undecidability bounds for matrix decision problems. Theoretical Computer Science, 3 - 13. https://doi.org/10.1016/j.tcs.2007.10.025

In this paper we consider several reachability problems such as vector reachability, membership in matrix semigroups and reachability problems in piecewise linear maps. Since all of these questions are undecidable in general, we work on lowering the... Read More about On undecidability bounds for matrix decision problems.