anchor.diff:              let mutable zi1 = 0.0
               let mutable count = 0;
               while flag && count < iter do
  -                if (zr1 * zr1 + zi1 * zi1 ) <= 4.0
  +                if zr1 * zr1 + zi1 * zi1 <= 4.0
                   then                        
                       let t = zr1
  -                    zr1 <- (zr1 * zr1 - zi1 * zi1 + cr)
  -                    zi1 <- (2.0 * zi1 * t + ci)
  +                    zr1 <- zr1 * zr1 - zi1 * zi1 + cr
  +                    zi1 <- 2.0 * zi1 * t + ci
                       count <- count + 1
                   else
                       flag <- false
  
positive.code: let mutable commandQueue = new CommandQueue(provider, provider.Devices |> Seq.head)
  
  let localWorkSize = 32
  //let d = (new _2D(400, 400, localWorkSize, localWorkSize))
  
  let mandelbrot =
      <@                            
  
negative.code: 
  open System.Drawing
  open System.Windows.Forms 
  
  let deviceType = DeviceType.Default
  
  