anchor.diff:      let prov = "http://www.w3.org/ns/prov#"
       let owl = "http://www.w3.org/2002/07/owl#"
       let bas = "http://nice.org.uk/ns/prov#"
  -    
  -  
  -  let fromActivity (act:Activity) =
  -    use g = new Graph ()
  +
  +    let add (g:IGraph) =
  +      g.BaseUri <- UriFactory.Create bas
  +      g.NamespaceMap.AddNamespace ("prov",UriFactory.Create prov)
  +      g.NamespaceMap.AddNamespace ("owl",UriFactory.Create owl)
  +      g.NamespaceMap.AddNamespace ("base",UriFactory.Create bas)
  +      
  +  let fromActivity  (g:IGraph) (act:Activity) =
  +   
       let literal s =
         g.CreateLiteralNode s :> INode
   
  
positive.code:  
    type Uri =
      | Uri of string * string
      with static member commit r c = Uri ("commit:",short c r)
           static member identity (c:LibGit2Sharp.Commit) = Uri ("individual:",c.Author.Email)
           static member versionedcontent c = Uri ("versionedcontent:",c)
           static member individual (r,f:LibGit2Sharp.TreeEntryChanges) = Uri ("individual:",f.Path)
           override x.ToString () = match x with | Uri (p,s) -> sprintf "%s:%s" p s 
           
    type FileVersion = {
      Id : Uri
  
negative.code:            (qn "prov:agent",puri act.User)
             (qn "prov:hadRole",literal "author, committer")
          ])
          ]) |> ignore
      g
  
    let ttl (tw:System.IO.TextWriter) g =
      let writer = CompressingTurtleWriter (CompressionLevel=3,PrettyPrintMode=true)
      writer.Save (g,tw) 
        
  module Main = 
    open Nessos.UnionArgParser
  