Take the 2-minute tour ×
MathOverflow is a question and answer site for professional mathematicians. It's 100% free, no registration required.

I am familiar with the work of Helmut Cajar, but his book is thirty years old and it's clear that there has been substantial progress since then. I have been spending a lot of time looking through mathscinet citations and am honestly a bit overwhelmed. Also, I'm not just interested in sets defined through restrictions on digits of their decimals expansions, but also similar results pertaining to continued fraction expansion, Cantor series expansions, the Luroth series expansion, Engel series expansion, etc.

share|improve this question
add comment

1 Answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.