.PS
.ps 20
##
lineht	=	2*lineht/3
## figure A-7
B1:	box "user-element" width 4*boxwid
B1a:	box invis with .w at B1.w
B1b:	box invis with .e at B1.e
B2:	box "DASE" with .ne at (B1.se.x, B1.se.y-lineht)
B4:	box "FTAM" with .nw at (B1.sw.x, B1.sw.y-lineht) shaded
B6:	box "ACSE" with .n at ((B4.n.x+B1.n.x)/2, B4.s.y-lineht)
B7:	box "ROSE" with .n at (B2.s.x, B2.s.y-lineht)
B5:	box with .n at (B1.n.x, B1.n.y+boxht/2) width 5*boxwid \
	height boxht+B1.n.y-B6.s.y
##
	line from B1a.s to B4.n
	line from (B4.s.x-boxwid/6, B4.s.y) to (B4.s.x-boxwid/6, B5.s.y)
	line from B1b.s to B2.n
	line from (B2.s.x+boxwid/6, B2.s.y) to B7.n
	line from B7.s to (B7.s.x, B5.s.y)
	line from (B4.s.x+boxwid/6, B4.s.y) to (B6.n.x-boxwid/6, B6.n.y)
	line from (B2.s.x-boxwid/6, B2.s.y) to (B6.n.x+boxwid/6, B6.n.y)
	line from B6.s to (B6.s.x, B5.s.y)
##
	line down from B5.s
	line dashed from (B5.w.x-linewid/2, B5.s.y-lineht) \
		    to   (B5.e.x+linewid/2, B5.s.y-lineht)
	move to (B5.e.x+linewid/2 , B5.s.y-lineht); \
	    "\ \ presentation service" ljust
##
.PE