There are five inverters with drive strengths from x2 to
x12 and a P:N ratio of 1.44. The effort tables
show the effort relative to the reference inverter in the vsclib,
the iv1v2x2, which has a P:N ratio of 2.25.
z:a'
cell width
power
Generic 0.13um typical timing (ps & ps/fF),
pin a.