fact: Definition num_stars m n (A : 'M[letter]_(m, n)) : nat := \sum_(m0 < m) \sum_(n0 < n) (A m0 n0 == Star).
imports: mathcomp(all_ssreflect ssralg fingroup finalg perm zmodp) mathcomp(matrix) ssr_ext ssralg_ext num_occ f2 ssrR hamming tanner linearcode