fact: Definition step_dist_it c r dests := foldl (fun (cd : _ * K) (mapping : (port * (port * {set port}))%type) => step_dist cd.1 cd.2 mapping.1 mapping.2) (c,r) (zip (enum (border (nodes c))) dests).
imports: mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix perm) ssr_ext ssralg_ext fdist subgraph_partition tanner