yosys/backends/btor/btor.ys

proc; 
opt; opt_const -mux_undef; opt;
rename -hide;;;
#converting pmux to mux
techmap -share_map pmux2mux.v;;
#explicit type conversion
splice; opt;
#extracting memories;
memory_dff -wr_only; memory_collect;;
#flatten design
flatten;;
#converting asyn memory write to syn memory
memory_unpack; 
#cell output to be a single wire
splitnets -driver;
setundef -zero -undriven;
opt;;;