 In the late 1940s, the Russian mathematician A.A. Markov began the development of an alternative form of constructive mathematics, RUSS, which is, essentially,  recursive function  theory with intuitionistic logic (Markov [1954], Kushner [1985]). In this variety the objects are defined by means of Gödel-numberings, and the procedures are all recursive; the main distinction between RUSS and the classical recursive analysis developed after the work of Turing, Church, and others in 1936 clarified the nature of computable processes is that the logic used in RUSS is intuitionistic.