anchor.diff:          // reset the Database
           using (new EntityFramework.EventStore.StoreContext(connection)) (fun c -> c.ClearTables())
   
  -        // let created = EntityFramework.EventStore.createDatabase connection
           Example.run connection
           printfn "Return to close"
           Console.ReadLine() |> ignore
  
positive.code:         let container = 
              context {
                  let! container = createContainer
                  do!  container |> moveTo     "Bremen"
                  do!  container |> loadGood   "Tomaten" (toT 3500.0<kg>)
                  do!  container |> moveTo     "Hamburg"
                  do!  container |> unloadGood "Tomaten" 2.5<t>
                  do!  container |> loadGood   "Fisch" 20.0<t>
                  return container
              } |> Context.evalUsing store
  
  
negative.code:             do! Context.add id ev
              return id }
  
      let shipTo (l : Location) (id : Id) : Context.Computation<unit> =
          context {
              do! assertExists id
              let ev = MovedTo l
              do! Context.add id ev }
  
      let load (g : Goods) (w : Weight) (id : Id) : Context.Computation<unit> =
          context {
              do! assertExists id
              let ev = Loaded (g,w)
              do! Context.add id ev }
  
      let unload (g : Goods) (w : Weight) (id : Id) : Context.Computation<unit> =
          context {
              let! loaded = Context.playback (goodWeight g) id
              if w > loaded then failwith "cannot unload more than is loaded"
  