Let be a well-ordered set. A subset of is said to be inductive if for every
Theorem (The principal of transitive induction). If J is a well-ordered set and is an inductive subset of , then .
Can someone help me get started on proving this. I am trying to show that [tex] J \subseteq J_0 [/Math] by choosing assuming that and showing that there is a contradiction. Is this a good approach and do you have any hints that I can use to get anywhere?
Ok so I made some progress, but I am not sure if I am moving in the right direction.
Proof: Choose and assume that Then
If then consider
Then this set has a least-element, call it It follows that
This is a contradiction.
If for this case, I can not find any kind of contradiction. Any suggestions?