!! White has an endless source of ko threats! Do not take kos unless you want to get it wrong !!
+ consider the lower right stone, it might be slightly important.
Enjoy!
(;AW[io]AW[jn]AW[ko]AB[im]AB[in]AB[km]AB[kn]AB[jq]AB[lo]AB[ho]AW[hn]AW[gn]AW[fn]AW[ln]AW[mn]AW[nn]AW[eo]AW[ep]AW[eq]AW[er]AW[oo]AW[op]AW[oq]AW[or]AB[jl]AB[hl]AB[ll]AB[il]AB[kl]AB[gl]AB[ml]AB[nl]AB[fl]C[Black wants to lower the value of white territory a bit. Unfortunately black is not good enough to find some way to do that.. can you help her?]AW[mr]AP[goproblems]
(;B[jo];W[jp]
(;B[kp]C[]
(;W[lp]C[Remember - white has unlimited source of ko threats!]
(;B[jm];W[kq]
(;B[ip]C[Cool!RIGHT])
(;B[jo];W[ip]C[And black cannot win the L4 ko]))
(;B[ip];W[kq]
(;B[jm]C[Very nice!RIGHT])
(;B[jo]C[NOTTHIS]))
(;B[jo]C[NOTTHIS]))
(;W[ip];B[jm];W[jo];B[hp]C[Ladder!RIGHT]))
(;B[ip]C[];W[kp];B[jm];W[jo])
(;B[jm];W[kp];B[ip];W[jo]))
(;B[ip];W[jo];B[kp];W[hp])
(;B[jm];W[jo]))