On the staircase,
the seating face is appeared by the run rises on the level one step up,
From above staircase,
The armchair emerges by heaving armrests up from the both side of the seating face.
This airmchair is nemed as 'stair-chair'.
'stair-chair’ is embeded on the pyramid-shape enclosed in with stairs.
Total forty 'stair-chair's appear on the pyramid-shaped stairs constructed by eighteen steps