“…Let S be any semiring. An operator T : M m,n (S) → M m,n (S) is called a (P, Q, B)-operator if there exist permutation matrices P and Q, and a matrix B ∈ M m,n (S) with no zero entries, such that In [4] linear preservers of extremal cases of classical matrix inequalities over fields were characterized. On the other hand, linear preservers for various rank functions over semirings have been the object of much study during the last 30 years, see for example [2]- [12].…”