anchor.diff:      let printGraph { Name = name; Contents = sg } =
           hsep [ String "digraph"
                  String name
  -               sg |> printSubgraph |> braced ]
  +               sg |> printSubgraph ]
   
   (*
    * Helper functions
  
positive.code:     let printEdge { Pre = s; Post = t; Cmd = vf } =
          hsep [ s |> sprintf "V%A" |> String
                 String "->"
                 t |> sprintf "V%A" |> String
                 String ";"]
  
      /// <summary>
      ///     Prints a <c>Subgraph</c>.
  
negative.code:         hsep [ sprintf "v%A" id |> String
                 squared (hsep [ String "label"
                                 String "="
                                 view |> printGView |> ssurround "\"" "\"" ])]
          |> withSemi
  
      /// <summary>
      ///     Prints an edge.
  