  We start with an ``algebraic'' RSK-correspondence due to Noumi and Yamada.
Given a matrix $X$, we consider a pyramidal array of solid minors of $X$. It
turns out that this array satisfies an algebraic variant of octahedron
recurrence. The main observation is that this array can also be constructed
with the help of some square `genetic' array. Next we tropicalize this
algebraic construction and consider $T$-{\em polarized} pyramidal arrays (that
is arrays satisfying octahedral relations). As a result we get several
bijections, viz: a) a linear bijection between non-negative arrays and
supermodular functions; b) a piecewise linear bijection between supermodular
functions and the so called infra-modular functions; c) a linear bijection
between infra-modular functions and plane partitions. A composition of these
bijections yields a bijection between non-negative arrays and plane partitions
coinciding with the modified RSK-correspondence.
