Forum:Can anyone help me about Taranovsky's notation?

See here for the notation. I feel puzzled about the definition about "n-built from below from b".

a is n+1-built from below from b iff the standard representation of a does not use ordinals above a except in the scope of an ordinal n-built from below from b.

So, I may ask some questions: Those questions block me from understanding the notation. Can anyone help me? hyp$hyp?cos&#38;cos (talk) 02:03, July 22, 2014 (UTC)
 * 1) the standard representation of a doesn't use something - what's "use" here?
 * In my opinion, if a=C(c,d) then a uses c and d, but what if c=C(e,f) (i.e. a=C(C(e,f),d)), does a use e and f?
 * 1) What's "ordinals in the scope of an ordinal n-built from below from b"?
 * Are "a is an ordinal in the scope of an ordinal n-built from below from b" and "a is an ordinal n-built from below from b" the same thing? Or "a is an ordinal in the scope of an ordinal n-built from below from b" means, there's an ordinal c that's an ordinal n-built from below from b, with c using a? Or something else?