anchor.diff:      return accum;
     }
     
  +  /*
     ConditionalConvergence(){
       CanvasRenderingContext2D context =
         (querySelector("#canvas") as CanvasElement).context2D;
     }
  -
  +*/
   }
   
   
  
positive.code:     List<double> accum = [0.0];
      double sum = 0.0;
      
      
      context.clearRect(0, 0, Width, Height);
      drawLine(0, 0, Width, 0, "black");
      drawLine(0, target, Width, target, "red", 2);
  
  
      for (var n=1; (target - sum).abs() > error; n++){
        if (include(sum, target, seq(n))) {
  
negative.code:   String targettxt;
  
    num target() => double.parse(targettxt);
  
    void onShadowRoot(ShadowRoot shadowRoot){
  //    accuExp = 2.0;
      CanvasRenderingContext2D context =
            (shadowRoot.querySelector("#canvas") as CanvasElement).context2D;
      drawLine(1,1, 20, 20, "red");
    }
    
    String result() =>
      "result" + printSeq(approxSeq(target(), example, pow(10.0, accuExp)));
  