What is the most efficient way to compare similar contents in two lists?

[Ethan Furman]

Chris Angelico wrote:
> On Tue, Jun 14, 2011 at 4:20 AM, geremy condra <debatem1 at gmail.com> wrote:
>> I know that, but I mean what were you talking about before if you
>> weren't talking about cmp?
> 
> Not sure what you mean. 

I suspect Geremy is referring to your "most of the batteries you're used 
to, included" comment -- which batteries are missing?

~Ethan~