Resumen de Limit Theorem for Semi-sequences in Extension Theory

Ivan Ivansic, Leonard L. Rubin

• Given an inverse sequence X = (Xi,pii+1) of topological spaces along with subspaces Ti of Xi and an infinite subset N* of the set of positive integers N, we define the concept of a semi-sequence T=(Ti,N*) and its semi-limit T=semi-lim T which is a subset of X=lim X. A notion of stability of T in X is defined along with extendability of X with respect to a given CW-complex K and T. We show that if the terms Xi of the inverse sequence are stratifiable, Ti is closed in Xi, and stability and extendability apply, then K is an absolute extensor for T. All previous extension theoretic limit theorems about inverse sequences are corollaries to this result.