.PS 8.5i
.ps 20
boxht = 4*boxht/5
## figure 13
B1:	box "SESSION SERVICES" width 3*boxwid
##
B2:	box "PRESENTATION SERVICES" width 3*boxwid with .sw at B1.nw
##
B3:	box "ASN.1" "" "TOOLS"  \
		with .se at (B1.ne.x+boxwid, B1.ne.y+boxht/2) height 2*boxht
##
B4:	box "DIRECTORY" "" "SERVICES" "" "[NBS]" with .se at B2.ne \
		width 3*boxwid/4
B6:	box "ASSOCIATION" "" "CONTROL" with .ne at B4.nw width 3*boxwid/4
B7:	box "REMOTE" "" "OPERATIONS" with .ne at B6.nw width 3*boxwid/4
B8:	box "RELIABLE" "" "TRANSFER"  with .ne at B7.nw width 3*boxwid/4
##
B9:	box "FTAM" with .se at B4.ne
B10:	box "VT" "" "[MITRE]" with .e at B9.w
B11:	box "MHS" "" "[UCL]" with .e at B10.w
##
B12:	box "FTAM/FTP GW" "" "[NBS]" with .s at B9.n
B13:	box "MHS/822 GW" "" "[NBS]" with .s at B11.n
##
.PE