User blog comment:P進大好きbot/New Googological Ruler/@comment-39605890-20191208005500/@comment-35470197-20191208012153

> You need to go a little higher in the Levy hierarchy to define it (you would actually run into paradoxes if you could it at the same level of hierarchy, I think).

Really? If a truth predicate for Σ_k-formulae is Σ_{k-1}, then it would cause paradoxes. But the Σ_k-ness of a truth predicate for Σ_k-formulae does not, I think. Could you please write down how it causes paradoxes?

> it would be better to say "it is very difficult to explicitly write down the formula for k that are large by human standards (if k is much larger than 100, for example)".

I thought that people who understand the issue on the complexity will not misunderstood the meanings, but your explanation looks better. I udated it. Thank you.