Before revision: In this paper we investigate the complexity of model selection and model testing in chemical reaction networks by formulating them as Euclidean distance problems .
After revision: In this paper we investigate the complexity of model selection and model testing in chemical reaction networks . We do this by formulating these tasks as a constrained optimization problem in Euclidean space. This optimization problem is known as a Euclidean distance problem; the complexity of solving this problem is measured by an invariant called the Euclidean distance (ED) degree .