// Supposed to look like curved wallpaper.  
// Two curves touching at the horizontal 
// in the middle of the page
paper 0
pen 80

//box command from p139 of Design By Numbers
command box l r t b
{
	repeat a l r
      	{
        	line a t a b
	}
}

command row t b
{
	set l 1
	set r 16
	set space 5
	set diff (r-1)
	box l r t b
	box (l+diff+space) (r+diff+space) t b
	box (l+(2*diff)+(2*space)) (r+(2*diff)+(2*space)) t b
	box (l+(3*diff)+(3*space)) (r+(3*diff)+(3*space)) t b
	box (l+(4*diff)+(4*space)) (r+(4*diff)+(4*space)) t b
}
set spaceb 4
//block
row (spaceb) (spaceb+15)
// 10
row ((2*spaceb)+15) ((2*spaceb) +15+10) 
// 6
row ((3*spaceb)+15+10) ((3*spaceb)+15+10+6)
// 2
row ((4*spaceb)+15+10+6) ((4*spaceb)+15+10+6+2)
// 1
row ((5*spaceb)+15+10+6+2) ((5*spaceb)+15+10+6+2)
//2
row ((6*spaceb)+15+10+6+2) ((6*spaceb)+15+10+6+2+2)
row ((7*spaceb)+15+10+6+2+2) ((7*spaceb)+15+10+6+2+2+6)
row ((8*spaceb)+15+10+6+2+2+6) ((8*spaceb)+15+10+6+2+2+6+10)
row ((9*spaceb)+15+10+6+2+2+6+10) ((9*spaceb)+15+10+6+2+2+6+10+15)