Hai-Feng Guo Wen Zheng Mahadevan Subramaniam L2C2: logic-based LSC consistency checking. 183-194 2009 PPDP http://doi.acm.org/10.1145/1599410.1599433 conf/ppdp/2009 db/conf/ppdp/ppdp2009.html#GuoZS09