The bottom of the tub has first and second portions vertically offset from one another with {HEAD ~ a connecting bridging member} forming {TAIL ~ a seat} 
The bottom of the tub has first and second portions vertically offset from one another with { HEAD ~ a connecting bridging member } forming { TAIL ~ a seat }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL