After the exchange of 1 for 2 white played tenuki (missing the atari at s3 - stupid me). Luckily white can still live (Of course I missed this in the game and carelessly lost an already won game :o) ). (My first tsumego - comments appreciated.)
(;AW[rs]AW[rr]AW[qq]AW[pq]AW[oq]AW[or]AW[pp]AW[qo]AW[pn]AW[pm]AW[qm]AW[sm]AW[rm]AW[ql]AB[qs]AB[qr]AB[pr]AB[ps]AB[os]AB[ns]AB[nr]AB[nq]AB[np]AB[op]AB[oo]AB[po]AB[on]AB[om]AB[ol]AB[pl]AB[pk]AB[qk]AB[rk]AB[rl]AB[sl]AB[rq]TR[rq]C[Black played the marked stone to kill your group. If you can live you still have a comfortable lead on the rest of the board.]LB[rs:1]LB[ps:2]AP[goproblems]
(;W[rp]
(;B[qp]C[It seems that the other black responses seem to live easier, so this path will be played out.]
(;W[ro]
(;B[sp]C[NOTTHIS]
(;W[so]
(;B[rn]C[Black still tries, but...NOTTHIS]
(;W[sq]
(;B[qq];W[sr]C[RIGHT])
(;B[sr]
(;W[qq]C[RIGHT])
(;W[ss];B[sr]C[:o( So close.])))
(;W[sr];B[qq];W[sq]C[:o)RIGHT]))
(;B[sq]C[NOTTHIS];W[rn]C[The best sequence for black, white lives with minimal points.RIGHT])))
(;B[rn]C[NOTTHIS]
(;W[sq]
(;B[qq];W[sr];B[sn];W[qn]C[:o)RIGHT])
(;B[sn];W[qn];B[qq]
(;W[sr]C[:o)RIGHT])
(;W[so];B[sr]C[So close...])))
(;W[sp];B[sn];W[qn];B[sq]C[Dead...])
(;W[sn];B[sp]C[:o(])
(;W[so];B[sr]C[:o(])))
(;W[rn];B[sp];W[so];B[ro]C[Ko is not your best option.])
(;W[so];B[rn];W[sq];B[ro]
(;W[sp];B[qn]C[:o(])
(;W[sn];B[sp]C[Ko is not your best option...]))
(;W[sq];B[ro]
(;W[rn]
(;B[qn])
(;B[sp]C[:o(]))
(;W[qq];B[qn]C[:o(])
(;W[so];B[qn]C[:o(]))
(;W[sp];B[ro];W[rn];B[qn]C[Ko is not your best option...])
(;W[qq];B[pq]C[Playing R3 is not good - it turns the correct path into a ko and doesn't help you to live. (I will not add all other wrong variations here.)];W[ro];B[sp];W[so];B[rn];W[sq];B[sr];W[qq]C[Ko for life...])
(;W[pq];B[ro]C[:o(]))
(;B[sq]
(;W[sp];B[qp];W[rn]C[RIGHT])
(;W[qp];B[sr];W[sp];B[rn];W[ss];B[qn];W[sq]C[RIGHT])))
(;W[qp];B[rp]
(;W[ro];B[sr]
(;W[so];B[rn]C[:o(])
(;W[rn];B[so]C[:o(]))
(;W[sq];B[ro];W[qn]C[Dead in gote...]))
(;W[rn];B[rp];W[ro];B[so];W[sq]
(;B[sr]C[:o(])
(;B[qp]C[:o(]))
(;W[ro];B[rp];W[so];B[rn];W[qp];B[sr]))