In 1984, due to deteriorating health, Lev Arkad'evich relinquished his teaching duties, and in 1985 his position within the faculty was changed to that of a 'senior researcher'.
Sa 1984, dahil sa deteriorating health, Lev Arkad'evich relinquished kanyang pagtuturo tungkulin, at sa 1985 ang kanyang posisyon sa loob ng mga guro ay nagbago na ng isang 'senior manaliksisk'.