 In (van Dalen 1978) a model is constructed of the axioms for the Creating Subject in the context of arithmetic and choice sequences, thus proving them to be consistent with intuitionistic arithmetic and certain parts of analysis. In (van Dalen 1982), CS is proven to be conservative over Heyting Arithmetic. Mathematical consequences of Kripke’s Schema can be found in (van Dalen 1997), where it is shown that KS and the continuity axioms reject Markov’s principle, while KS together with Markov’s principle implies the principle of the excluded middle. 