Large ordinals
  Let $j$ be an elementary embedding of $V_{\lambda}$ into $V_{\lambda}$ that is not the identity, and let $\kappa$ be the critical point of $j$. Let $\Cal A$ be the closure of $\{j\}$ under the operation $a (b)$ of application, and let $\Omega$ be the closure of $\{\kappa\}$ under the operation $\min \{\xi: a(\xi) \ge b(\alpha)\}$. We give a complete description of the set $\Omega$ under an assumption (Threshold Hypothesis) on cyclic left distributive algebras. 
Thomas Jech