Abstract ? The Mondex Electronic Purse is an outstanding example of industrial scale formal refinement, and was the first verification to achieve ITSEC level E6 certification. A formal abstract model ...
the objects of all sets X ? V, morphisms of all mappings from X into Y, with the usual composition of mappings. By a mapping we mean a triple where f is a function from X into Y. The notations and con...
Summary. In this article some basic theorems about singletons, pairs, power sets, unions of families of sets, and the cartesian product of two sets are proved.
D is a set, f is a finite sequence of elements of D, and G is a matrix over D. One can prove the following propositions: (1) If len f = 2, then f ?2 = < f1, f2>. (2) If k + 1 = len f, then f ?(k + 1) ...
function from a set X into a set Y, denoted by ?Function of X,Y ?, the set of all functions from a set X into a set Y, denoted by Funcs(X,Y), and the permutation of a set (mode Permutation of X, where...