Hi Raghu, Your description in the original post was rather unclear - I assumed the same as Lawrence. Something like this is probably what you want? procedure(CCFfilterReversedLists(l) let(((revListTable makeTable('reversedLists nil))) setof(sublist l unless(revListTable[sublist] when(listp(sublist) revListTable[reverse(sublist)]=t ) t ) ) ) ) Regards, Andrew.Image may be NSFW.
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