(;AB[bs]AB[br]AB[cq]AB[cp]AB[ap]AB[bo]AW[an]AW[bn]AW[cn]AW[co]AW[dp]AW[eo]AW[cr]AW[dr]AP[goproblems]
(;W[ar];B[aq]
(;W[bp]C[RIGHT])
(;W[bq];B[bp];W[ao];B[as]))
(;W[bp];B[bq];W[ao];B[ar]C[ko])
(;W[ao];B[bp]
(;W[ar];B[aq]TR[dq]C[Black would not escape if the marked liberty was filled];W[dq];B[as])
(;W[aq]
(;B[ar]TR[dq]C[Black would not escape if the marked liberty was filled])
(;B[bq]TR[dq]C[This is a mistake by Black];W[ar])))
(;W[aq];B[ar]
(;W[bp];B[bq];W[ao];B[bp])
(;W[ao];B[bq];W[bp]C[ko])
(;W[bq];B[bp])))