anchor.diff:          // TODO(CaptainHayashi): Use the model for something.
           onNodes (Utils.optimiseWith optR optA verbose
                        [ ("graph-collapse-nops", true, collapseNops)
  -                       ("graph-collapse-ites", true, collapseITEs) ] )
  +                       ("graph-collapse-ites", true, collapseITEs)
  +                       ("x-graph-drop-local-midview",
  +                        false,
  +                        dropLocalMidView model.Locals) ] )
   
       /// <summary>
       ///     Optimises a model over graphs.
  
positive.code:                     else (removed, g, Some nName)
                  | _ -> (removed, g, Some nName)
  
  
      /// <summary>
      ///     Performs a node-wise optimisation on every node in the graph.
  
negative.code:     let glueNames { InEdge.Name = a } { OutEdge.Name = b } =
          String.concat "__" [ a ; b ]
  
      /// <summary>
      ///     Decides whether a command is local.
      /// </summary>
      /// <param name="tVars">
      ///     A <c>VarMap</c> of thread-local variables.
      /// </param>
      /// <returns>
      ///     A function returning True only if (but not necessarily if)
      ///     the given command is local (uses only local variables).
      /// </returns>
      let isLocalCommand tVars : Command -> bool =
          // A command is local if, for all of its funcs...
          List.forall
              (fun { Params = ps } ->
                   // ...for all of the parameters in said funcs...
                   Seq.forall
                       (// ...for all of the variables in said parameters...
                        varsIn
                        >> Set.toSeq
                        >> Seq.forall
                               (// ...the variable is thread-local.
                                fun c ->
                                    match (Map.tryFind (stripMark c) tVars) with
                                    | Some _ -> true
                                    | _ -> false))
                       ps)
  
      /// <summary>
      ///     Removes a node if it is an ITE-guarded view.
  