pic2(indexloop)

import geometry;

size(2cm,0);
defaultpen(fontsize(12pt));
dotfactor = 4;

fill(box((-0.5, -6 ), (0.5, -12) ), lightyellow+opacity(0.5));

for(int i=7; i<12; ++i){
  for(int j=0; j<1; ++j)
  {
    label("$u_{"+string(i)+"}$", (j,-i));
  }
}