“…The reason for this is that strong information on the resolution of singularities is available for analytic functions of two variables, for instance, by means of Puiseux series expansions of roots, whereas the situation for multivariate functions of more than two variables is substantially more complex. Nevertheless, there has been a lot of progress on the question as to how to construct more elementary and "concrete" resolutions of singularities for real analytic multivariate functions, giving more detailed information than what Hironaka's celebrated theorem [35] on the resolution of singularities would yield, for instance, in work by Bierstone and P. D. Milman [7], [8], Sussmann [64], Parusiński [53], [54], Greenblatt [28], [30], Collins, Greenleaf, and Pramanik [15], among others. These techniques have already led to a very good understanding of, for instance, the sublevel estimation problem for slices of the surfaces in direction to the Gaussian normal, and the related determination of critical integrability indices, in independent work by Greenblatt [28], [30], and also Collins, Greenleaf, and Pramanik [15], by rather different methods.…”