design -save preopt

simplemap
techmap -map +/gate2lut.v -D LUT_WIDTH=4
select -assert-count 1 t:$lut
design -stash postopt

design -copy-from preopt -as preopt top
design -copy-from postopt -as postopt top
equiv_make preopt postopt equiv
prep -flatten -top equiv
equiv_induct
equiv_status -assert