  The longitudinal polarization of anti-Lambda produced in the currant
fragmentation region of polarized lepton DIS off polarized and unpolarized
target is described both in the simple formalism with factorized fragmentation
functions as well as within intrinsic strangeness model using string
fragmentation implemented into event generator LEPTO.
  It is demonstrated that the the measurement of anti-Lambda polarization and
its dependence on the target polarization can serve as a filter for
(un)polarized anti-strangeness distribution function of nucleon.
