  Let H be a hypergraph on n vertices with the property that no edge contains
another. We prove some results for a special case of the Isolation Lemma when
the label set for the edges of H can only take two values. Given any set of
vertices S and an edge e, the weight of S in e is the size of e plus the size
of the intersection of S and e. A versal S for an edge e is a set of vertices
with weight in e smaller than the weight in any other edge. We show that H
always has at least n + 1 versals except if H is either the set of all
singletons T_n or the complement of T_n or the 4-cycle graph. In those
exceptional cases there are only n versals.
