ABSTRACT
This chapter considers the category W of archimedean lattice-ordered groups with distinguished non-negative weak order unit, with unit-preserving ℓ-homomorphisms. Each object of W is an “ℓ-group of continuous functions” via the Yosida representation, which says that A is isomorphic to an ℓ-group of continuous, extended-real valued, amost-finite functions on a certain compact Hausdorff space Y(A). It seems that the scheme in this chapter accounts for virtually all the functorial hulls which have been studied. There are, however, some quasi-algebraic classes which are not algebraic, and among these, ones with bigger hulls than the C(Rω)-closure. The chapter essentially sums up the topics discussed in terms of operators defined in the proofs of A.
