(;GM[1]FF[4]SZ[19]
GN[]
PC[http://senseis.xmp.net/?RetrogradeAnalysisProblem4/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?RetrogradeAnalysisProblem4/Solution

]
PL[B]

AB[ea][eb][cc][dc][ec][ad][bd][cd]
AW[bb][cb][db][ac][bc]
CR[ha][hb][hc][hd][he][af][bf][cf][df][ef][ff][gf][hf]

;B[ba]C[B1]MN[1]
;W[aa]C[W2]MN[2]
;B[ab]C[B3]MN[3]

;CR[ha][hb][hc][hd][he][af][bf][cf][df][ef][ff][gf][hf]
)
