Regarding synchronous logic circuits, much of the work to date considered abstract CRN schemes. One exception is Silva and McClenaghan (2004), where a system of actual chemical reactions is given, together with a precise molecular implementation for gates complete with a thermodynamic analysis of how the system would evolve, though only for simple gate designs. In Cook et al. (2009) we see the construction and composition of simple logic gates based upon catalytic reactions, but they do not mention control flow or systematic component design in a dual rail setting. In Senum and Riedel (2011) the authors propose CRNs for an inverter, an incrementer, a decrementer and a copier; their designs are based on two rate constants, “fast” and “slow”, and thus are not rate-independent, in contrast to the designs presented here.