Abstract. In this paper we introduce an unified framework for topological manipulation on triangulated 2manifolds with or without boundary. We show that there are two kinds of prim...
We investigate which polynomials can possibly occur as factors in the denominators of rational solutions of a given partial linear difference equation (PLDE). Two kinds of polynom...
Maurer machines are much closer to real computers than Turing machines. Computer instructions play a prominent part in Maurer machines. We show a straightforward way to simulate Tu...
We construct a model with an indecisive precipitous ideal and a model with a precipitous ideal with a non precipitous normal ideal below it. Such kind of examples were previously ...
We construct a polynomial-time algorithm to approximate the branch-width of certain symmetric submodular functions, and give two applications. The first is to graph "clique-wi...