anchor.diff:  //                        t'.GetFields(BF.Instance ||| BF.Public ||| BF.NonPublic)
                           |> Seq.choose (fun (KeyValue(compName, f)) ->
                               match f with
  -                            | Metadata.InstanceField name 
  -                            | Metadata.OptionalField name -> 
  +                            | Metadata.InstanceField name, _, _ 
  +                            | Metadata.OptionalField name, _, _ -> 
                                   comp.GetFieldAttributes(td, compName) |> Option.map (fun (ftyp, fattrs) ->
                                       let isQuery =
                                           fattrs
  
positive.code:                                         name, queryItem, ty
                                      else name, QueryItem.NotQuery, ftyp
                                  )
                              | Metadata.StaticField _ -> None
                          ) 
                          |> List.ofSeq
                      let isHole (n: string) = n.StartsWith "{" && n.EndsWith "}"
  
negative.code:                 let render = c.Arguments.[0]
                  Lambda([go; action],
                      Conditional (TypeCheck (Var action, targ),
                          some targ (Application (render, [Var go; Var action], Pure, Some 2)),
                          none targ
                      )
                  )
  