I was watching battousai's tygem games on youtube. Thought I spot something but alas nothing so I had to improvise.
(;AB[bc]AW[cc]AW[bd]AW[be]AW[bf]AB[cd]AB[ce]AB[cg]AB[bg]AB[dg]AB[eg]AB[dh]AB[di]AB[cj]AB[ck]AB[cl]AB[bl]AB[dl]AB[cm]AB[ff]AW[bk]AW[bj]AW[ai]AW[bh]AW[ci]AW[dj]AW[dk]AB[gf]AB[gg]AW[ee]AW[ef]AW[fe]AB[jl]AW[bm]AW[fj]AW[eh]AW[fg]AW[gh]AW[fh]AW[hg]AW[ih]AB[gk]AB[hk]AB[ij]AB[ii]LB[mj:T]AB[hf]AW[he]AW[fl]AW[ig]AB[jf]AW[il]AB[jm]AB[jn]AB[go]AB[hl]AB[hm]AW[im]AW[in]AB[gm]AB[gn]AW[io]AW[ip]AB[jo]AB[jp]AB[hn]AB[ho]AB[em]AW[dn]AB[ep]AB[bb]AB[ac]AW[cb]AW[ca]AW[ba]AW[aa]AW[cf]AB[df]AB[de]AB[dd]AW[fd]AW[fc]AW[ec]AW[db]AB[ad]TR[de]AW[ab]AW[gr]C[Can white kill the marked group with at least a ko? Tenuki if you do not think so.]AP[goproblems]
(;W[mj]C[Correct. White did not have a kill.RIGHT])
(;W[ei];B[ag]
(;W[ah];B[af];W[ae];B[bc]
(;W[ac];B[ad];W[be];B[ak]C[No ko])
(;W[ak];B[ad];W[be];B[bf];W[bd];B[ac]))
(;W[ae]
(;B[ah]C[Yeah white can not escape])
(;B[ch]C[Mistake];W[ah]C[Only ko];B[ak];W[ed];B[al];W[dc])
(;B[ak]C[Mistake];W[ed];B[al];W[dc];B[aj];W[ah];B[bc];W[ac];B[bi];W[bj];B[bk];W[bb];B[bi]C[You got your ko. But it is not good enough])))
(;W[ag];B[ei]
(;W[ej];B[fi];W[gi];B[gj];W[fk];B[hh];W[hi];B[hj];W[hh];B[if];W[jh];B[kh];W[ji];B[ki];W[jj];B[kj];W[jk];B[kk];W[ik];B[iq];W[hp];B[hq];W[gp];B[gq];W[fp];B[fq];W[fo];B[eo];W[fn];B[fm];W[en]
(;B[el]C[Black survives])
(;B[gl]))
(;W[fi];B[ej];W[ek];B[fk])))
