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

The four-space extension]
PL[W]

AB[cd][pd]

;W[ic]C[W1]MN[1]
;B[gc]C[B2]MN[2]
;W[nc]C[W3]MN[3]

;
)
