(;GM[1]FF[4]SZ[19]
GN[Extension]
PC[http://senseis.xmp.net/?StaircaseStatistics]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?StaircaseStatistics

Extension]
PL[B]

AB[ii][jj]
AW[ij][jk]

;B[kj]C[B1]MN[1]

;
)
