simple objc/swarm question

[Rick Riolo]

Please excuse the novice objC/swarm question.
I must be missing something basic.

Why is that when I try the following:

#import <swarmobject.h>
#import <collections.h>

@interface AgentList : List {

}
@end

I get the compiler error:

  Cannot find interface declaration for `List', superclass of `AgentList'

I was thinking just as I could subclass off SwarmObject, say, 
I could subclass off of List, adding variables and methods
as I need to my subclass of List.  (eg I might want a method
to return the n-th item in the list, not just fisrt and last.)

What fundemental idea am I missing here?
Is there a way to do what I want?

thanks!
 - r

Rick Riolo                       address@hidden
Program for Study of Complex Systems (PSCS)
1061 Randall Lab     University of Michigan
Ann Arbor MI 48109-1120
http://pscs.physics.lsa.umich.edu/rlr-home.html