Note:
In Fig's. -7(a), -7(b), -7(e)
the "odd" stack is shown as the vertical stack.
The structure contains left- & right-handed nodes,
like those shown in Fig's. -7(c) & -7(d) respectively.
They are interdistributed among each other in a manner
as shown schematically in Fig. -7(e).
These left- & right-handed nodes are
interdistributed among each other
in such a fashion that
single-file columns of only left-handed nodes
alternate with
single-file columns of only right-handed nodes.
These (2) kinds of columns, seen "end-on,"
are interdistributed among each other
as black & white checkerboard squares
are among each other.
These columns are coincident - in a one-with-one fashion -
with the transits of the odd stack.
