User blog comment:Syst3ms/A dump of my (on hold) shot at well-defining pi definition/@comment-31966679-20180917215057/@comment-35870936-20180917230728

\(\Omega_1\) (or just \(\Omega\) ) is the first uncountable cardinal, but it can also be thought of as the first ordinal with cardinality greater than \(\omega\). Then, \(\Omega_2\) is the first ordinal with cardinality greater than \(\Omega_1\). In general, \(\Omega_{\alpha+1}\) is the first ordinal with cardinality greater than \(\Omega_\alpha\).