# The Going Down Theorem Idea: for $A$ a normal domain and $f: A\to B$ an integral extension, $f^\sharp: \spec B\to \spec A$ is an open map. # Statements ![Statement of the going down theorem](attachments/Pasted%20image%2020220114184528.png) ![Pasted image 20220114184615.png](Pasted%20image%2020220114184615.png) ![](attachments/Pasted%20image%2020220120131243.png) ## Proof ![Proof of the going down theorem](attachments/Pasted%20image%2020220114184542.png)