-- the results are now shifted Left by one cell, until we hit the blank we wrote (we can't hit a blank before!)
delete (Q "COPYBACK", Zero) = (Q "COPYZERO", Blank, L)
delete (Q "COPYBACK", Zero) = (Q "COPYZERO", Blank, L)
delete (Q "COPYBACK", Zero) = (Q "COPYZERO", Blank, L)