The group of parallel metal lines in the horizontal direction of the crossbar structure may be realized by stacking alternating layers of metal and insulator, patterning the stacks into stripes, and etching vertically to form mesas that include {HEAD ~ stacks} of {TAIL ~ isolated horizontal metal lines} 
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The group of parallel metal lines in the horizontal direction of the crossbar structure may be realized by stacking alternating layers of metal and insulator , patterning the stacks into stripes , and etching vertically to form mesas that include { HEAD ~ stacks } of { TAIL ~ isolated horizontal metal lines }
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL