fact: Definition graph_of_trace (pns : _ * l.-tuple _) := switch_step_dist_it lam rho (start_graph pns.1) (start_dist pns.1) pns.2.
imports: mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix perm) ssr_ext ssralg_ext fdist subgraph_partition tanner