anchor.diff:          { /// <summary>
             ///      The name of the edge.
             /// </summary>
  -          Name : string
  +          Name : EdgeID
             /// <summary>
             ///      The source of this edge.
             /// </summary>
  -          Src : string
  +          Src : NodeID
             /// <summary>
             ///      The command this edge represents.
             /// </summary>
  
positive.code: [<AutoOpen>]
  module Types =
      /// <summary>
      ///     Enumeration of node types.
      ///
      ///     <para>
  
negative.code: ///     The edges of <paramref name="_arg1" />, as name-edge pairs.
  ///     This is wrapped in a Chessie result over <c>Error</c>.
  /// </returns>
  let axiomatiseGraph : Graph -> (string * Axiom<SVGView, Command>) seq =
      mapEdges
          (fun { Name = n; SrcView = s ; DestView = t ; Command = c } ->
              (n, { Pre = match s with InnerView v -> v
  