RENDICONTI DELL'ISTITUTO DI MATEMATICA DELL'UNIVERSITAÌ€ DI TRIESTE
Abstract
The problem of finding compact Hausdorff sequential spaces of sequential order $\alpha \le \omega_1$ is important and highly nontrivial. A solution has been searched in ZFC, but unsuccessfully
up to now. Classically it was solved under CH, and more recently
under MA up to order four. We present here a construction of a space of order three that appears simpler than previous constructions.
