Strong Approximation Property for Baer Orderings on *-Fields

Abstract

Let (D, *) be a *-field with [D: Z(D)] being finite. Our main objective is to show that the space of all Baer orderings (resp. weak *-orderings) of (D, *) satisfies the strong approximation property iff every Baer ordering of (D, *) is in fact a weak *-ordering. This shows that the notions of Baer orderings and weak *-orderings are respectively the "correct" analogues for semiorderings and orderings. We also intro-duce the concept of Baer formally real *-fields and Baer preorderings. We prove that a *-field admits a Baer ordering iff it is Baer formally real. In addition, some new results on weak *-orderings are also discussed. © 1994 Academic Press. All rights reserved.