# fodor

1. ### Club Sets and Fodor's Lemma

I'm trying to obtain a better understanding of what a club set is to get started. I understand what it means for a set to be unbounded with respect to a limit ordinal $\kappa$, but I'm having trouble grasping what it means for a set to be closed in $\kappa$...
2. ### fodor theorem

Let \kappa-cardinal \lambda-ordinal,C \subset \kappa C \in dom if and only if [ \forall \lambda <\kappa (sup (C\cap\lambda)=\lambda \Rightarrow \lambda \in C)] club_{k} =\lbrace C \subset\kappa : C \in dom andsupC=\kappa\rbrace how to show that: (fodor theorem) If \forall_{\alpha <\kappa}...