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

Derived shapes]
PL[B]

AB[bh][ch][dh][di][dj][bk][ck][dk]
AW[bg][cg][dg][eh][ei][ej][ek][bl][cl][dl]
CR[ag][dh][dk][al]


;CR[ag][dh][dk][al]
)
