Michael L. Case Alan Mishchenko Robert K. Brayton Jason Baumgartner Hari Mony Invariant-Strengthened Elimination of Dependent State Elements. 1-9 2008 FMCAD http://dx.doi.org/10.1109/FMCAD.2008.ECP.6 conf/fmcad/2008 db/conf/fmcad/fmcad2008.html#CaseMBBM08