anchor.diff:          evalContent content slice history effectSystem
   
       and private evalRepeat shift repetition incrementAspects content (slice : Slice) history effectSystem =
  -    
  +
           // eval repeat either as iterative or cycling
           let slice = { slice with Elevation = slice.Elevation + shift }
           match repetition with
  -    
  +
           // eval iterative repeat
           | Iterate count ->
               Array.fold
  
positive.code:                 | _ -> Log.info ("Expected Aspect for definition '" + definitionName + "'."); slice
              | None -> Log.info ("Could not find definition with name '" + definitionName + "'."); slice
          | Aspects aspects ->
              Array.fold
                  (fun slice aspect -> evalAspect aspect slice effectSystem)
                  slice
                  aspects
      
      and private evalAspects aspects slice effectSystem =
          Array.fold (fun slice aspect -> evalAspect aspect slice effectSystem) slice aspects
  
negative.code:         // build sprite views
          let effectSystem =
              if slice.Enabled then
                  let mutable transform = Transform.makeDefault ()
                  transform.Position <- slice.Position - slice.Size * 0.5f // assume centering
                  transform.Scale <- slice.Scale
                  transform.Offset <- slice.Offset
                  transform.Size <- slice.Size
                  transform.Angles <- slice.Angles
                  transform.Elevation <- slice.Elevation
                  let spriteView =
                      Render (transform.Elevation, transform.Position.Y, font,
                          TextDescriptor 
  