Anonymous Ruby Box Generation

http://www.w3.org/TR/css3-ruby/#box-fixup
2.2. Anonymous Ruby Box Generation

I'm having a little trouble understanding how this works such that we 
end up with all ruby layout structures properly parented.

[1]
If the ruby markup is

<ruby>振<rt>ふ</rt>り<rt>り</rt>仮<rt>が</rt>名<rt>な</rt></ruby>

How do the base characters get anonymous ruby-base boxes?



[2]
If the ruby markup is

<ruby><rb>振<rb>り<rb>仮<rb>名<rt>ふ<rt>り</rt><rt>が<rt>な</ruby>

step 3 says

"Within each ruby base container, each sequence of inline-level boxes is 
wrapped in an anonymous ruby base box"

Shouldn't this say:

"Within each ruby base container, each of the inline-level boxes is 
wrapped in an anonymous ruby base box"

since the sequence is equivalent to the ruby base container by the 
definition in step 2.



[3]
If the ruby markup is

<ruby><rb>振<span>り</span>仮名<rt>annotations</ruby>

wouldn't step 3 produce 3 ruby bases where only one was intended?