Before revision:  For CFL with cardinality facility cost (CFL-CFC), we present an LP-based 4-approximation algorithm, which  surpasses the long-standing ratio of~5 due to Levi et al  that ages up for decades since 2004.
After revision:  For CFL with cardinality facility cost (CFL-CFC), we present an LP-based 4-approximation algorithm, which surpasses the long-standing ratio of~5 due to Levi et al . that ages up for decades since 2004.