Definition 2 The characteristic function χA: R → B of the set

Reversible computing is a concept reflecting physical reversibility. Until now several reversible systems have been investigated. In a series of pa-pers Kenichi Morita defines the rotary element RE, that is a reversible logic element. By reversibility, he understands [2] that ’every computa-tion process can be traced backward uniquely from the end to the start. In other words, they are backward deterministic systems’. He shows [1] that any reversible Turing machine can be realized as a circuit composed of RE’s only. Our purpose in this paper is to use the asynchronous systems theory and the real time for the modeling of the ideal rotary element.