fact: Definition pinsker_function_spec c q := - log (1 - q) - 4 * c * q ^ 2.
imports: mathcomp(all_ssreflect ssralg ssrnum) Reals Lra mathcomp(mathcomp_extra Rstruct reals) ssrR Reals_ext realType_ext Ranalysis_ext ssr_ext logb ln_facts bigop_ext convex fdist divergence variation_dist partition_inequality