(;AB[ap]AB[cp]AB[bp]AB[cr]AW[bo]AW[co]AW[dp]AW[eq]AW[er]AW[dn]C[b to live locally (no ko, elementary)]AP[goproblems]
(;B[ar];W[bq]
(;B[dr]
(;W[cq]
(;B[dq];W[br]
(;B[bs]C[nice!RIGHT])
(;B[aq];W[bs]MA[as]MA[cs]C[can't approach]))
(;B[br];W[dq]))
(;W[bs];B[br]C[RIGHT]))
(;B[cq];W[bs]MA[br]MA[cs]C[dead])
(;B[br];W[cq])
(;B[dq];W[dr]MA[cq]MA[bs]C[dead]))
(;B[dq];W[dr]
(;B[ar];W[bq])
(;B[cq];W[cs]MA[as]MA[br]MA[ar]MA[aq]MA[bq])
(;B[bq];W[ar]))
(;B[bq];W[ar]MA[as]MA[bs]MA[br]MA[ar]MA[aq]TR[dr]TR[dq])
(;B[bs];W[ar]MA[as]MA[ar]MA[br]MA[bq]MA[aq])
(;B[dr];W[ds]
(;B[ar];W[bs];B[cs];W[bq]
(;B[br]C[nice!RIGHT])
(;B[cq];W[br])
(;B[dq];W[br]))
(;B[bs];W[ar]MA[as]MA[ar]MA[br]MA[bq]MA[aq])
(;B[bq];W[ar]
(;B[dq];W[bs];B[cs];W[br])
(;B[bs];W[dq])
(;B[cs];W[dq]))
(;B[dq];W[bs];B[cs];W[br])
(;B[br];W[ar]
(;B[dq]C[nice!RIGHT])
(;B[aq];W[cq]
(;B[dq];W[bs];B[as]C[ko (running out may not be a valid threat)])
(;B[as];W[dq]MA[cs]MA[bq])
(;B[cs];W[dq]MA[bq]MA[as]))
(;B[cs];W[dq]
(;B[cq];W[aq];B[as];W[bs]C[ko or escape, depends on surrounding])
(;B[aq];W[cq])
(;B[as];W[cq];B[bq];W[bs]C[ko or escape, depends on surrounding]))
(;B[as]C[tricky? see next problem])))
(;B[br];W[cq]MA[ar]MA[bq]))