=INDIRECT(ADDRESS(ROW(),COLUMN()))<>OFFSET(INDIRECT("<name of sheet>!A1"),ROW()-1,COLUMN()-1,1,1)
Asumes comparison starts from A1 cell.
Built using: https://productforums.google.com/forum/#!topic/docs/GfSEU3ngRvo
=INDIRECT(ADDRESS(ROW(),COLUMN()))<>OFFSET(INDIRECT("<name of sheet>!A1"),ROW()-1,COLUMN()-1,1,1)
Asumes comparison starts from A1 cell.
Built using: https://productforums.google.com/forum/#!topic/docs/GfSEU3ngRvo