{HEAD ~ A width Pb} of {TAIL ~ the bottom portion} of each protrusion formed between the striations and a width Wb of the lower base satisfy Pb<Wb 
of
{ HEAD ~ A width Pb } of { TAIL ~ the bottom portion } of each protrusion formed between the striations and a width Wb of the lower base satisfy Pb < Wb
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL 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