design -load read
hierarchy -top case_overlap
-prep
+#prep # Do not prep otherwise $pmux's overlapping entry will get removed
+proc
design -save gold
muxpack
-#opt # Do not opt otherwise $pmux's overlapping entry will get removed
+opt
stat
select -assert-count 0 t:$mux
-select -assert-count 1 t:$pmux
+select -assert-count 2 t:$pmux
design -stash gate
design -import gold -as gold
design -import gate -as gate