fact: Hypothesis Hy : tuple_of_row y \in V.-shell (tuple_of_row x).
imports: mathcomp(all_ssreflect ssralg finset matrix) Reals mathcomp(Rstruct) ssrR realType_ext Reals_ext ssr_ext ssralg_ext logb ln_facts num_occ fdist entropy channel divergence types jtypes proba jfdist_cond