fact: Definition checksubsum n (V : {set 'I_n}) (x : 'rV['F_2]_n) : bool := (\sum_(n0 in V) x ``_ n0) == 0.
imports: mathcomp(all_ssreflect ssralg fingroup finalg perm zmodp) mathcomp(matrix vector) Reals ssralg_ext ssrR Reals_ext f2 fdist channel tanner linearcode pproba