918252.fig.0032a
(a) The base case with only positive polar nodes being active
918252.fig.0032b
(b) The base case with only negative polar nodes being active
918252.fig.0032c
(c) Induction step for the positive polarity case
Figure 32: Induction proof for that the long main structure can be unit-disk covered by nodes with the same polarity. Note that for the main structure of a polarity inverter, .