I have a list of dates, strings and integers:
lis = {{DateObject[{2000,1,1}],"a",1,"w"},{DateObject[{1999,12,31}],"a",1,"x"},{DateObject[{1999,12,31}],"a",2,"z"}
I would like to identify pairs of elements of lis that have identical values in their 2nd and 3rd position (in this case, "a" and 1), and then delete the older element of the pair, to leave:
res = {{DateObject[{2000,1,1}],"a",1,"w"},{DateObject[{1999,12,31}],"a",2,"z"}}
I realize this is likely be a duplicate question, but can't seem to find it; thanks for any thoughts.