Let G be a finite group and A a Z[G] module.

Definition (1.1). A simply connected CW complex X is of type (A, n) if G operates on X cellularly, and modules.

This paper is devoted to the study of convergence and variation of operator spectra with respect to the distance G of Gokhburg and Markus [5] for subspaces and linear operators in a Banach space. We use the convention of Kato [7] and refer to convergence with respect to G as generalizedconvergence.

Let G be a graph with multiple edges. Let f be a function from the vertex set V(G) of G to the non-negative integers. An f-factor of G is a spanning subgraph F of G such that the degree (valence) of each vertex x in F is f(x). A theorem of Fulkerson, Hoffman and McAndrew [1] gives necessary and sufficient conditions to have an f-factor for a graph G with the odd-cycle property; i.e., if G has the property that either any two of its odd (simple) cycles have a common vertex, or there exists a pair of vertices, one from each cycle, which is joined by an edge. They proved this theorem using integer programming techniques, with a rather long proof. We show that this is a corollary of Tutte's f-factor theorem.

Recently the theory of cardinal polynomial spline interpolation was extended to cardinals -splines [3]. Let

be a polynomial with only real zeros. Denote the set of zeros by . If is the associated differential operator, the null-space