We present symbolic and numerical algorithms for a computer search in the Coxeter spectral classification problems. One of the main aims of the paper is to study finite posets I that are principal, i.e., the rational ...

The concepts of a self-hereditary stable tube T and a hereditary stable tube T in a module category modA are introduced, where A is a finite dimensional algebra over an algebraically closed field. Characterisations ...

The existence of large indecomposable right Rmodules over a right artinian ring R is discussed in connection with the pure semisimplicity problem and the endo-wildness of the category Mod(R) of right R-modules. Some ...