Two on a Tower have done...while other eminent critics (I wonder if they are the same) print the most cutting rebukes you can conceive—show me (to my amazement) that I am quite an immoral person...” Two on a Tower Two on a Tower (1882) is a novel by English author Thomas Hardy, classified by him as a romance and fantasy and now regarded as one of his minor works. The book is one of Hardy's Wessex novels, set in a parallel version of late Victorian Dorset. Hardy placed an epigraph at the beginning of this book. The epigraph is from a Richard Crashaw poem,
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