fact: Definition stopset (s : {set 'I_n}) := [forall m0, #| s :&: `V m0 | != 1%N].
imports: mathcomp(all_ssreflect ssralg fingroup finalg perm zmodp) mathcomp(matrix) f2 ssr_ext ssralg_ext max_subset num_occ hamming ldpc_erasure tanner linearcode