only apply with elementary path consistency notion

def get_opt_repairs_add_remove_edges_greedy(instance,nm, edges):
  '''
   only apply with elementary path consistency notion
  '''

  sem      = [sign_cons_prg, elem_path_prg, fwd_prop_prg, bwd_prop_prg]
  inst     = instance.to_file()
  f_edges  = TermSet(edges).to_file()
  prg      = [ inst, f_edges, remove_edges_prg,
               min_repairs_prg, show_rep_prg,
             ] + sem + scenfit
  coptions = str(nm)+' --project --opt-strategy=5 --opt-mode=optN --quiet=1'
  solver   = GringoClasp(clasp_options=coptions)
  models   = solver.run(prg, collapseTerms=True, collapseAtoms=False)
  #print(models)
  #nscenfit  = models[0].score[0]
  #nrepscore = models[0].score[1]
  #print('scenfit:   ', nscenfit)
  #print('repscore:  ', nrepscore)

  os.unlink(f_edges)
  os.unlink(inst)
  return models