origin = ( 3,8 )
	cht = 1.1*cht; cwid = 1.25*cwid;
	ellipse '1'
	ellipse '2' with .nw at last ellipse.se
	right; move to ( 6,4.25 )
		circlerad = 0.15
	SORT:	circle invisible 'SORT'
		downright
		arrow from SORT.se ->
	LIST:	circle invisible 'LIST'
		downleft
		arrow from LIST.sw ->
		arrow from SORT.sw ->
	POSET:	circle invisible 'POSET'
		arrow from POSET.sw ->
		circle invisible 'TRIV'
		arrow downright from POSET.se ->
		circle invisible 'BOOL'