Problem 1f.

command sqr x y
{
   repeat b x (x+20)
   {
      pen (100-b)
      line b y b (y+20)
   }
}
forever
{
   repeat n 25 75
   {
      line 25 25 n 75
      pen (n-100)
   }
   paper 77
   pen (/2)
   sqr () ()
   pen (100-/2)
   sqr (+23) (+23)
}

-gary escudero