User blog comment:Nayuta Ito/tetrational logarithm/@comment-1605058-20150731105254/@comment-25337554-20150801045320

First, I changed x and y in ↓og so that it will be monotonic increase.

For domain of y and x, the limit exists unless y is too big and x is too small.

(e.g. If the base(y) is 10, you can't put a number less than 2.09..., or you have to take a log of negative number.)