The Equational Approach to CF2 Semantics
  We introduce a family of new equational semantics for argumentation networks which can handle odd and even loops in a uniform manner. We offer one version of equational semantics which is equivalent to CF2 semantics, and a better version which gives the same results as traditional Dung semantics for even loops but can still handle odd loops. 
Dov M. Gabbay
cs.AI cs.LO