The set splitting problem asks, for a collection of subsets of a finite set
, whether
can be partitioned into two sets
and
such that every member of
meets both parts. In other words, it asks whether there is
a set partition
satisfying
for every .
Equivalently, the members of are to be colored with two colors
so that no member of
is monochromatic. The decision
problem is NP-complete (Lovász
1973).