(;AW[eb]AW[dc]AW[fc]AW[bd]AW[cd]AW[dd]AB[ab]AB[db]AB[bc]AB[cc]
(;B[ba];W[cb]
(;B[da];W[ea]
(;B[ca]C[RIGHT])
(;B[bb];W[ca]))
(;B[ca];W[da])
(;B[bb];W[da]))
(;B[ca];W[ba]
(;B[bb];W[ea])
(;B[da];W[bb])
(;B[aa];W[bb]))
(;B[cb];W[ba])
(;B[da];W[ba]C[vital point of the 'bulky five'])
(;B[ea];W[fa]
(;B[ba];W[cb]
(;B[da];W[ca])
(;B[ca];W[da]))
(;B[ca];W[ba];B[bb];W[da]C[Ko - you can do without it.])
(;B[da];W[ba]C[Vital point of the 'bulky five']))
(;B[bb];W[ca]
(;B[ba];W[da])
(;B[da];W[ba]))
(;B[ad];W[cb]))