- INSTANCE: Graph .
- SOLUTION:
An independent sequence for
*G*, i.e., a sequence of independent vertices of*G*such that, for all*i < m*, a vertex exists which is adjacent to but is not adjacent to any for . - MEASURE:
Length of the sequence, i.e.,
*m*.

*Good News:*Approximable within [224].*Bad News:*As hard as MAXIMUM INDEPENDENT SET [224].