fact: Definition unsplit_prod (m n : nat) (i : 'I_m * 'I_n) : 'I_(m * n) := let (i, j) := i in Ordinal (unsplit_prodp i j).
imports: HB(structures) mathcomp(all_ssreflect ssralg fingroup perm matrix) mathcomp(mathcomp_extra boolp classical_sets Rstruct) mathcomp(ssrnum ereal) mathcomp(lra Rstruct reals) Reals ssrR Reals_ext Ranalysis_ext ssr_ext ssralg_ext logb realType_ext fdist