(;GM[1]FF[4]SZ[19]
GN[2 empty triangles - is the 2nd one unnecessary?]
PC[http://senseis.xmp.net/?GoodEmptyTriangle]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?GoodEmptyTriangle

2 empty triangles - is the 2nd one unnecessary?]
PL[W]

AB[jc][oc][rc][fd][ld][md][qd][ge][cf][df][gf][if][hg][dh][gh][hh][nh][cj][pj][qj][dk][cl][fl][ol][pl][qm][jp][kp][lp][op][jq][mq][nq][pq][ir][jr][qr]
AW[hb][dd][hd][rd][be][ce][ee][ie][ke][le][re][ff][qf][fg][gg][ph][qi][dj][cm][dm][pm][fn][in][ln][no][oo][qo][ip][np][cq][gq][iq][kq][qq][rq][hr]

;W[lh]C[W1]MN[1]
;B[oh]C[B2]MN[2]
;W[pi]C[W3]MN[3]
;B[oi]C[B4]MN[4]

;
)
