proposition: Lemma msg_none_eq (i1 i2 i : id') k : i1 != i -> i2 != i -> @msg _ _ i1 i2 (Some i) k =1 @msg _ _ i1 i2 None k.
proof: Proof. move=> Hi1 Hi2 [id0 tag0 ch0 up0 down0] /=. case: ifP => [/eqP [] |] Hi1'. by rewrite Hi1' eqxx in Hi1. case: ifP => [/eqP [] | //] Hi2'. by rewrite Hi2' eqxx in Hi2. Qed.
imports: Wf_nat Init.Wf Recdef Reals mathcomp(all_ssreflect perm zmodp matrix ssralg) mathcomp(Rstruct) ssrR Reals_ext ssr_ext ssralg_ext bigop_ext f2 fdist channel pproba linearcode subgraph_partition tanner tanner_partition summary ldpc checksum ldpc_algo