0.00/0.02 YES 0.00/0.02 We consider the system theBenchmark. 0.00/0.02 0.00/0.02 Alphabet: 0.00/0.02 0.00/0.02 f : [] --> a -> b -> c 0.00/0.02 f1 : [a] --> b -> c 0.00/0.02 f2 : [a * b] --> c 0.00/0.02 0.00/0.02 Rules: 0.00/0.02 0.00/0.02 f x => f1(x) 0.00/0.02 f1(x) y => f2(x, y) 0.00/0.02 0.00/0.02 This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). 0.00/0.02 0.00/0.02 We use rule removal, following [Kop12, Theorem 2.23]. 0.00/0.02 0.00/0.02 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 0.00/0.02 0.00/0.02 f(X) >? f1(X) 0.00/0.02 f1(X) Y >? f2(X, Y) 0.00/0.02 0.00/0.02 We orient these requirements with a polynomial interpretation in the natural numbers. 0.00/0.02 0.00/0.02 The following interpretation satisfies the requirements: 0.00/0.02 0.00/0.02 f = \y0y1.3 + 3y0 + 3y1 0.00/0.02 f1 = \y0y1.y0 0.00/0.02 f2 = \y0y1.y0 + y1 0.00/0.02 0.00/0.02 Using this interpretation, the requirements translate to: 0.00/0.02 0.00/0.02 [[f(_x0)]] = \y0.3 + 3y0 + 3x0 > \y0.x0 = [[f1(_x0)]] 0.00/0.02 [[f1(_x0) _x1]] = x0 + x1 >= x0 + x1 = [[f2(_x0, _x1)]] 0.00/0.02 0.00/0.02 We can thus remove the following rules: 0.00/0.02 0.00/0.02 f(X) => f1(X) 0.00/0.02 0.00/0.02 We use rule removal, following [Kop12, Theorem 2.23]. 0.00/0.02 0.00/0.02 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 0.00/0.02 0.00/0.02 f1(X, Y) >? f2(X, Y) 0.00/0.02 0.00/0.02 We orient these requirements with a polynomial interpretation in the natural numbers. 0.00/0.02 0.00/0.02 The following interpretation satisfies the requirements: 0.00/0.02 0.00/0.02 f1 = \y0y1.3 + 3y0 + 3y1 0.00/0.02 f2 = \y0y1.y0 + y1 0.00/0.02 0.00/0.02 Using this interpretation, the requirements translate to: 0.00/0.02 0.00/0.02 [[f1(_x0, _x1)]] = 3 + 3x0 + 3x1 > x0 + x1 = [[f2(_x0, _x1)]] 0.00/0.02 0.00/0.02 We can thus remove the following rules: 0.00/0.02 0.00/0.02 f1(X, Y) => f2(X, Y) 0.00/0.02 0.00/0.02 All rules were succesfully removed. Thus, termination of the original system has been reduced to termination of the beta-rule, which is well-known to hold. 0.00/0.02 0.00/0.02 0.00/0.02 +++ Citations +++ 0.00/0.02 0.00/0.02 [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. 0.00/0.02 EOF