NO Problem: f(n__b(),X,n__c()) -> f(X,c(),X) c() -> b() b() -> n__b() c() -> n__c() activate(n__b()) -> b() activate(n__c()) -> c() activate(X) -> X Proof: Matrix Interpretation Processor: dim=1 interpretation: [b] = 6, [n__c] = 6, [c] = 6, [activate](x0) = 4x0 + 6, [n__b] = 6, [f](x0, x1, x2) = 2x0 + 3x1 + x2 + 4 orientation: f(n__b(),X,n__c()) = 3X + 22 >= 3X + 22 = f(X,c(),X) c() = 6 >= 6 = b() b() = 6 >= 6 = n__b() c() = 6 >= 6 = n__c() activate(n__b()) = 30 >= 6 = b() activate(n__c()) = 30 >= 6 = c() activate(X) = 4X + 6 >= X = X problem: f(n__b(),X,n__c()) -> f(X,c(),X) c() -> b() b() -> n__b() c() -> n__c() Unfolding Processor: loop length: 4 terms: f(c(),c(),c()) f(c(),c(),n__c()) f(b(),c(),n__c()) f(n__b(),c(),n__c()) context: [] substitution: Qed