determining {HEAD ~ a first positive transition temporal relationship} of {TAIL ~ the first positive transition} to a first reference positive transition time; and 
of
determining { HEAD ~ a first positive transition temporal relationship } of { TAIL ~ the first positive transition } to a first reference positive transition time ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH