On split extensions of preordered groups

Abstract

We investigate the behaviour of split extensions in the category $OrdGrp$ of (pre)- ordered groups. Namely we show that the lexicographic order plays a key role on the existence of compatible orders for semidirect products, establishing necessary and sufficient conditions for such existence; we prove that the Split Short Five Lemma holds for (stably) strong split extensions, and identify classes of split extensions which admit a classifier.