{HEAD ~ Each molecular moiety} may be different from every other molecular moiety within the array, such that the array is a “combinatorial” library of {TAIL ~ the different molecular moieties} 
{ HEAD ~ Each molecular moiety } may be different from every other molecular moiety within the array , such that the array is a “ combinatorial ” library of { TAIL ~ the different molecular moieties }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL