Resolution:
## Figure 7.
Two sets of possible configurations of an undecided variable gadget and the corresponding
transformation of the covering. (Note that if edge {c, c'} is also missing in either initial configuration on the left, that the corresponding
configuration on the right still applies, since c and c' do not intersect any vertex outside this variable gadget, and the number of hyperedges
removed has not increased.)
Maňuch |