  L.L. Maksimova and L. Esakia, V. Meskhi showed that the modal logic S4 has
exactly 5 pretabular extensions: PM1-PM5. In this paper, we study and
systematize the problem of unification for all given pretabular logics. We
showed that PM2,PM3 have finitary, and PM1,PM4,PM5 have unitary types of
unification. Complete sets of unifiers in logics are described.
