Host_Alias questions

[root]

I have a few quick questions regarding Host_Alias.

1.  Is there a way to specify Host_Alias -1 host (for example, all hosts except hostX)?  In this example, the user could use sudo on all hosts except hostX.

2.  Can you add more than one Host_Alias to a User Specification?  Lets say I have yo Host_Alias definitions:

Host_Alias	Hosts1=hostA,hostB,hostC
Host_Alias	Hosts2=hostD,hostE,hostF

Could I set up UserX with this definition:

UserX	Hosts1=ALL Hosts2=ALL

If I can, amd I using the corrct syntax?

3.  Can a Host_Alias definition overlap with another?

Example:

Host_Alias	Hosts1=hostA,hostB,hostC
Host_Alias	Hosts2=hostB,hostD,hostE,hostF

I read the man page for sudoers but the EXAMPLES do not cover any of these situations.  I also looked online but all the resources seem to use the man page as documentation.  Thanks for any help.

chris