main = let
  emptyFB           = FrameBuffer ((colorImage1 (V4 0.0 0.0 0.4 1.0))
  rasterCtx         = TriangleCtx CullNone PolygonFill NoOffset LastVertex
  fragmentCtx       = accumulationContext (DepthOp Less False) -- ERROR
  vertexShader ((v))    = VertexOut v 1.0 () (Smooth v)
  vertexStream      = fetch "stream" Triangle (Attribute "position" :: ((Vec 4 Float)))
  primitiveStream   = Transform vertexShader vertexStream
  fragmentStream    = Rasterize rasterCtx primitiveStream
  fragmentShader = FragmentShader $ \((v)) -> (V4 1.0 0.0 0.0 1.0)
  frame             = accumulate fragmentCtx PassAll fragmentShader fragmentStream emptyFB
 in ScreenOut frame