On the fundamental group of a schurian algebra

摘要

We show that, for a class of schurian algebras, which we call schurian almost triangular, the fundamental group of the algebra is isomorphic to the fundamental group of an associated simplicial complex. Moreover, we obtain a simple presentation of this group in terms of generators and relations. Finally we use it to obtain easy short proofs of some known, facts on the simple connectedness of incidence algebras. [References: 25]