anchor.diff:  
           let refs =
             project.References
  -          |> Seq.choose Project.getAssemblyLocation
  +          |> Seq.collect Project.getAssemblyLocations
             |> Seq.append portableRefs
             |> Seq.toList
   
  
positive.code:            match referencedAssemblies |> Seq.tryFind Project.isPortable with
             | Some _ -> true
             | None -> project.References
                       |> Seq.choose (fun r -> if r.ReferenceType = ReferenceType.Assembly then Project.getAssemblyLocation r else None)
                       |> Seq.tryFind isAssemblyPortable
                       |> Option.isSome
  
  
negative.code:               if isNull reference.Package then
                    tryGetFromHintPath()
                else 
                    if reference.Include <> "System" then
                        let assembly = 
                                reference.Package.Assemblies
                                |> Seq.find (fun a -> a.Name = reference.Include)
                        [assembly.Location]
                    else
                        reference.Package.Assemblies
                        |> Seq.map (fun a -> a.Location)
                        |> List.ofSeq
  
            | ReferenceType.Project -> 
                let referencedProject = reference.Project :?> DotNetProject
                let reference =
                    referencedProject.GetReferencedAssemblyProjects (getCurrentConfigurationOrDefault referencedProject)
                    |> Seq.tryFind(fun p -> p.Name = reference.Reference)
  
                match reference with
                    | Some ref ->
                        let output = ref.GetOutputFileName(getCurrentConfigurationOrDefault ref)
                        [output.FullPath.ToString()]
                    | _ -> []
            | _ -> []
  
        let getDefaultTargetFramework (runtime:TargetRuntime) =
            let newest_net_framework_folder (best:TargetFramework,best_version:int[]) (candidate_framework:TargetFramework) =
  