{HEAD ~ The machine} includes {TAIL ~ a rotatable drum} having a spaced pair of cylindrically contoured surfaces 
{ HEAD ~ The machine } includes { TAIL ~ a rotatable drum } having a spaced pair of cylindrically contoured surfaces
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH