Obviously, every internal column is alternately an L-column and an R-column, and the changes occur every horizontal step.
i], i [greater than] 1, is an L-column immediately after step [h.
j], j [is greater than] k, is an L-column immediately after step [h.
Intuitively, the R-column and the L-column that are at [K.
N] contains a foot of height x, we can no longer guarantee that every L-column generated on the left border contains at least ?
3] + O(T), then immediately after step t every second L-column arriving in [Z.
N] is designed so that when an L-column with feet ?
4] + O(1), then immediately after step t every L-column leaving [Z.
7], then immediately after step t every L-column arriving in Y has a foot of height ?
7], the first such L-column reaches the left end of [Z.
They move to the left and once the first such L-column reaches the end of [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII], all L-columns in [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] have feet of height ?
While R-columns "move to the right" and L-columns "move to the left", the vertical steps make efforts to sort these columns.