+(defun with (agentset fn)
+ "WITH AGENTSET FN => RESULT-AGENTSET
+
+ARGUMENTS AND VALUES:
+
+ AGENTSET: a NetLogo agentset
+ FN: a boolean function, run on each agent to determine if included
+ RESULT-AGENTSET: an agentset of valid agents
+
+DESCRIPTION:
+
+ WITH is equivalent to with in NetLogo.
+
+ Returns a new agentset containing only those agents that reported true
+ when FN is called.
+
+ See http://ccl.northwestern.edu/netlogo/docs/dictionary.html#with"
+ (list->agentset
+ (remove-if-not
+ (lambda (agent)
+ (let ((*myself* *self*) (*self* agent)) (funcall fn)))
+ (agentset-list agentset))
+ (agentset-breed agentset)))
+