{HEAD ~ The shaping means} is then moved proximally along {TAIL ~ a first predetermined contour}, to a proximal area on the tube, and then along a second predetermined contour, symmetrical to the first predetermined contour, back to the point of entry 
is moved proximally along
{ HEAD ~ The shaping means } is then moved proximally along { TAIL ~ a first predetermined contour } , to a proximal area on the tube , and then along a second predetermined contour , symmetrical to the first predetermined contour , back to the point of entry
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH