Wessex the ensuing Norman Conquest of England, and as the Norman kings soon did away with the great earldoms of the late Anglo-Saxon period, 1066 marks the extinction of Wessex as a political unit. From the second edition (1989) of the "Oxford English Dictionary": Wessex 1. The name of a kingdom in south-west England in Anglo-Saxon times, used by Thomas Hardy as the name of the county in which his stories are set (corresponding approximately to Dorset, Somerset, Hampshire, and Wiltshire) and since used as a name for south-west England or this part of it. Wessex is often symbolised by a
S (set theory) S (set theory) S is an axiomatic set theory set out by George Boolos in his 1989 article, "Iteration Again". S, a first-order theory, is two-sorted because its ontology includes “stages” as well as sets. Boolos designed S to embody his understanding of the “iterative conception of set“ and the associated iterative hierarchy. S has the important property that all axioms of Zermelo set theory "Z", except the axiom of extensionality and the axiom of choice, are theorems of S or a slight modification thereof. Any grouping together of mathematical, abstract, or concrete objects, however formed, is a "collection", a