anchor.diff:      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))) {
  
positive.code: 
  const int Width= 1000;
  
  CanvasRenderingContext2D context ;
  
  
  @Component(
  
negative.code:     templateUrl: 'packages/mathlets/conditionalconvergence.html',
      cssUrl: 'packages/mathlets/conditionalconvergence.css',
      publishAs: 'cmp')
  class ConditionalConvergence extends ShadowRootAware{
    double accuExp = 0.0;
    
    CanvasRenderingContext2D context ;
    
    var spacing = 5;
  
  