Computer simplification of formulas in linear systems theory

Currently, the three most popular commercial computer algebra systems are Mathematica, Maple, and MACSYMA. These systems provide a wide variety of symbolic computation facilities for commutative algebra and contain implementations of powerful algorithms in that domain. The Grobner Basis Algorithm, for example, is an important tool used in computation with commutative algebras and in solving systems of polynomial equations, On the other hand, most of the computation involved in linear control theory is performed on matrices, and these do not commute, A typical issue of IEEE TRANSACTIONS ON AUTOMATIC CONTROL is full of linear systems and computations with their coefficient matrices A B C D's or partitions of them into block matrices, Mathematica, Maple, and MACSYMA are weak in the area of noncommutative operations, They allow a user to declare an operation to be noncommutative but provide very fem commands for manipulating such operations and no powerful algorithmic tools, It is the purpose of this paper to report on applications of a powerful tool, a noncommutative version of the Grobner Basis algorithm, The commutative version of this algorithm is implemented in most major computer algebra packages, The noncommutative version is relatively new: [5].