In this section we present our dual-rail designs for an asynchronous computing device in CRNs. The key component is the Muller C-element, whose design is inspired by the well known Approximate Majority (AM) CRN (Angluin et al. 2008). We begin by providing a detailed justification for our C-element design, and then describe the remaining simple components, including latches, logic gates and control flow. Finally, we present complex circuits such as the pipeline, queue and adder.