1) That their equation (2) is logically equivalent to our (hereafter, D-K) sufficiency conditions presented in the 1974 issue of this Review. 2) That the assumption of degree zero homogeneity (in the variables m and p) of the utility function serves completely to characterize the class of illusion-free demand functions derivable from ordinal utility theory. 3) That it is possible to reinstate the usual Slutsky properties by adopting the semi-separable utility function given in their equation (4).