% `Nport+.m4'
.PS
Twoport: nport("2-port")

 "W1a" above rjust at Twoport.W1a
 "W1b" below rjust at Twoport.W1b
 "E1a" above ljust at Twoport.E1a
 "E1b" below ljust at Twoport.E1b

Nport: nport(wid 1.5 ht 1 fill_(.9) "n-port",1,2,3,4) \
  with .Box.sw at Twoport.Box.se+(1.5,0)

  "W1a" rjust at Nport.W1a
  "W1b" rjust at Nport.W1b

 "E1a" ljust at Nport.E1a
 "E3b" ljust at Nport.E3b

 "N1a" above at Nport.N1a
 "N2b" above at Nport.N2b

 "S1a" below at Nport.S1a
 "S4b" below at Nport.S4b

 "$\cdots$" at 0.5<Nport.N1a,Nport.N2b>+(0,.10)
 "$\cdots$" at 0.5<Nport.S1a,Nport.S4b>+(0,-.10)
 "$\vdots$" at 0.5<Nport.E1a,Nport.E3b>+(.15,.05)

 `"\tt nport(\"2-port\")"' at Twoport.s+(0,-.4)
 `"\tt nport(wid 1.5 ht 1 fill\_(.9) \"n-port\",1,2,3,4)"' \
  at Nport.s+(0,-.4)
.PE