define(`nullor',`nport(`$1'
{`"${}0$"' at Box.w ljust
`"$\infty$"' at Box.e rjust},shift($@))')
N: nullor
`"\tt nullor"' at last [].s+(0,-3pt__) below
G: gyrator with .sw at N.se+(0.5,0)
`"\tt gyrator"' at G.s+(0,-3pt__) below
I: gyrator(invis,,0,N) with .w at G.e+(0.5,0)
`"\tt gyrator(invis,{,}0,N)"' at I.s
V: gyrator(invis wid boxht,,0,NV) with .w at I.e+(1,0)
`"\tt gyrator(invis wid boxht,{,}0,NV)"' at V.s+(0,-3pt__) below
