I'm trying to figure out a way to answer the following task:
Suppose that for every $ \alpha, \beta < \omega_1 $ there exists a $ \gamma < \omega_1 $ such that $ \aleph_{\alpha}^{\aleph_\beta} = \aleph_\gamma $. Compute the cardinality of the following set $$\{(\aleph_{\omega_1})^\kappa : 1 \leq \kappa < \aleph_{\omega_1}\}$$
Obviously the answer is $ \leq \aleph_{\omega_1} $, but I don't have any great ideas on how to pursue the answer - should I seek the other inequality? How do i use the assumption about exponentiating cardinals?
I would appreciate some hints
Well, it looks as if I'm going to answer my own question.
It's not difficult to prove the following result, knowing Tarski's and Bukovský's identities for exponentiating cardinals:
So what the assumption gives us is that if $ \lambda, \mu < \kappa = \aleph_{\omega_1}$ and by this lemma, this set will contain only two elements: $ \aleph_{\omega_1}, \aleph_{\omega_1}^{\omega_1} $
I would appreciate a verification of this answer