fact: Definition tree'_of_graph (l : nat) c (pn : {set port}) : tree l.+1.*2 kv := Node [seq tree_of_graph l.*2.+1 (negk kv) (switch c) p | p in pn].
imports: mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix perm) ssr_ext ssralg_ext fdist subgraph_partition tanner