The head pipe has {TAIL ~ a supporting surface portion} corresponding to {HEAD ~ the surface} of the aforementioned warped intermediate portion 
The head pipe has { TAIL ~ a supporting surface portion } corresponding to { HEAD ~ the surface } of the aforementioned warped intermediate portion
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH