anchor.diff:  
           let cmdprint = vsep (List.map printCommand term.Commands)
   
  -        vsep [ String "procedure" <+> String name <+> (varprint |> parened) 
  -               String "requires" 
  -               Indent reqprint 
  -               String "ensures" 
  +        vsep [ String "procedure" <+> String name <+> (varprint |> parened)
  +               String "requires"
  +               Indent reqprint
  +               String "ensures"
                  Indent ensprint
                  braced (Indent cmdprint)
  -             ]  
  +             ]
   
       /// <summary>
       ///     Print a pragma if it has some meaning in GRASShopper.
  
positive.code: open Starling.Backends.Z3
  open Starling.Optimiser.Graph
  
  [<AutoOpen>] 
  module Types =
      /// <summary>A Grasshopper variable shadowing a Starling variable.</summary>
      type ShadowVar =
  
negative.code: ///     This model contains procedures for each term in the existing model,
  ///     as well as procedures for deferred checks.
  /// </summary>
  let grassModel (model : Backends.Z3.Types.ZModel) : Result<GrassModel,Error> =
      let fails = extractFailures model
      let failSeq = Map.toSeq fails
  
  