(
;
AB [ap][bp][cp][dp][ep][fq][fr][fs]
AW [ao][bo][co][do][eo][fo][fp][gp][gq][gr][gs][eq]
C [Can black keep everything here? Assume white has a large but not infinite supply of ko threats. (No => play at N (G5); Yes => prove it)]
LB [go:N]
(; B [go]; AB [ao][bo][co][do][eo][fo][fp][gp][gq][gr][gs][eq] AW [ap][bp][cp][dp][ep][fq][fr][fs] W [er] C [Why not?] (; B [dq]; W [dr]; B [cq]; W [bq]; B [cr]; W [br]; B [cs]; W [bs])(; B [dr]; W [dq]; B [cr]; W [br] (; B [cs]; W [cq] (; B [bs]; W [ar])(; B [es]; W [eq]))(; B [es]; W [ds]; B [cs]; W [cq]; B [es]; W [eq] (; B [bs]; W [ar])(; B [ar]; W [bs])(; B [aq]; W [bq])(; B [bq]; W [aq]))))
(; B [er]; W [dr]; B [dq]; W [cr]; B [br]; W [cs] (; B [es]; W [bq]; B [ar]; W [bs]; B [cq] C [RIGHT])(; B [cq] C [RIGHT])(; B [bq] C [RIGHT])(; B [ar]; W [es] (; B [ds] C [Ko.])(; B [eq]; W [bq] C [Ko.]))(; B [bs]; W [es] (; B [ds] C [Ko.])(; B [eq]; W [bq] (; B [ds] C [Ko.])(; B [aq]; W [ar] C [Double snapback (not even a ko anymore, as cae pointed out).])(; B [ar]; W [cq] C [Ko.]))))
)