hierarchy -top top
proc
flatten
-#ERROR: Found 4 unproven $equiv cells in 'equiv_status -assert'.
-#equiv_opt -assert -map +/ecp5/cells_sim.v synth_ecp5 # equivalency check
-equiv_opt -map +/ecp5/cells_sim.v synth_ecp5 # equivalency check
+equiv_opt -assert -map +/ecp5/cells_sim.v synth_ecp5 # equivalency check
design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
cd top # Constrain all select calls below inside the top module
select -assert-count 1 t:L6MUX21