.subckt inv<> GND Vdd x y
M0_ GND x y GND nch W=5u L=2u
M1_ Vdd x y Vdd pch W=5u L=2u
.ends

.subckt foo<> GND Vdd a
xp GND Vdd a b inv<>
.ends

.subckt bar<> GND Vdd a
xp GND Vdd a foo<>
.ends

xnone GND Vdd none.a bar<>

