The two notebooks computes residue curve maps for the methyl acetate and isopropyl acetate chemistries at atmospheric pressure. These calculations involve solving a complex system of differential algebraic equations (DAEs). This can be readily achieved using the built-in function of Mathematica, FindRoot and Euler's method of integration. The governing equations, which depend on transformed compositions, can be found in the pioneering paper by Barbosa, D., and M. F. Doherty, Chemical Engineering Science, 3 (43), 541-550, 1988. Appropriate equations must be used to compute vapor-liquid equilibrium when there is dimerization in the gas phase. These equations have been derived by 1/ Marek, J.& Standart, G., Colln Czech. Chem. Commun., Engl. Edn, (19) 1074-1084, 1954; 2/ Marek, J. Colln Czech. Chem. Commun., Engl. Edn, (20) 1490-1502, 1955. Acetic acid, the associating component, is present in both quaternary mixtures. The occurrence of a chemical reaction leads to the disappearance of an ...