Originally, reaction systems were introduced to describe in a formal way the interactions between biochemical reactions taking place in living cells. They are also investigated as an abstract model... Show moreOriginally, reaction systems were introduced to describe in a formal way the interactions between biochemical reactions taking place in living cells. They are also investigated as an abstract model of interactive computation. A reaction system is determined by a finite background set of entities and a finite set of reactions. Each reaction specifies the entities that it needs to be able to occur, the entities which block its execution, and the entities that it produces if it occurs. Based on the entities available in a state of the system, all reactions of the system that are enabled take place and together produce the entities that form the next state. In this paper we compare reactions in terms of their enabledness and results. We investigate three partial orders on reactions that build on two definitions of equivalence of (sets of) reactions. It is demonstrated how each partial order defines a lattice (with greatest lower bounds and least upper bounds) for all nontrivial reactions. Together, these orders provide an insight in possible redundancies and (re)combinations of the reactions of a reaction system. (C) 2020 Elsevier B.V. All rights reserved. Show less
We present a method for molecular computing which relies on blocking (inactivating) this part of the total library of molecules that does not contribute to (finding) a solution—this happens... Show moreWe present a method for molecular computing which relies on blocking (inactivating) this part of the total library of molecules that does not contribute to (finding) a solution—this happens essentially in one biostep (after the input has been read). The method is explained by presenting a DNA based algorithm for solving (albeit in the theoretical sense only!) the satisfiability problem. Show less
