The completeness characterization of C ( L ) , L a locale

The result of the title is: an archimedean (cid:2) -group with weak unit A is (isomorphic to) C ( L ) for some (identifiable) locale L (or, R L op , L op the opposite frame) iff A is divisible and “ ∗ -complete,” (a type of sequential completeness). This is from Ball and Hager (Positivity 10:165–199, 2006), and is revisited here, with streamlined proof.