  We discuss, using recent results on the Landauer's bound in multivalued
logic, the difficulties and pitfalls of how to apply this principle. The
presentation is based on Szilard's version of Maxwell's demon experiment and
use of equilibrium Thermodynamics. Different versions of
thermodynamical/mechanical memory are presented - one-hot encoding version and
the implementation based on reversed Szilard's experiment. Relation of the
Landauer's principle to Galois connection is explained in detail.
