In this section, we will describe the inference of the reactivity ratios and how the likelihood (denoted Φ by Scott et al. ) marginalized over the independent variable can be written in a closed form. The expressions here follow closely those presented in . We will be quite specific to the problem at hand given in equation ( ), but everything is applicable to any other model without loss of generality. This section is very technical and we provide some chemist friendly illustrative examples and a more detailed explanation in appendix A.