PS
# sixpole.m4
define(`biquad',`[
In: Here
 resistor(right_)
E: dot
 resistor
 dot
 {capacitor(down_,C); ground(,T)}
 line right_ elen_/3
 { dot
   line up_ elen_
   amp(to (E,Here),elen_/2)
   capacitor(from E to Here,C) }
 amp(right_,elen_/2)
 Out: Here
 ]')

cct_init
define(`elen_',linewid)

 biquad
 biquad with .In at last [].Out+(-linewid/4,0)
 biquad with .In at last [].Out+(-linewid/4,0)
PE