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 0 : [] --> a 0.00/0.02 id : [] --> a -> a 0.00/0.02 plus : [a] --> a -> a 0.00/0.02 s : [a] --> a 0.00/0.02 0.00/0.02 Rules: 0.00/0.02 0.00/0.02 id x => x 0.00/0.02 plus(0) => id 0.00/0.02 plus(s(x)) y => s(plus(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 id X >? X 0.00/0.02 plus(0) >? id 0.00/0.02 plus(s(X)) Y >? s(plus(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 0 = 3 0.00/0.02 id = \y0.3y0 0.00/0.02 plus = \y0y1.3 + 3y0 + 3y1 0.00/0.02 s = \y0.3 + y0 0.00/0.02 0.00/0.02 Using this interpretation, the requirements translate to: 0.00/0.02 0.00/0.02 [[id _x0]] = 4x0 >= x0 = [[_x0]] 0.00/0.02 [[plus(0)]] = \y0.12 + 3y0 > \y0.3y0 = [[id]] 0.00/0.02 [[plus(s(_x0)) _x1]] = 12 + 3x0 + 4x1 > 6 + 3x0 + 4x1 = [[s(plus(_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 plus(0) => id 0.00/0.02 plus(s(X)) Y => s(plus(X) Y) 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 id(X) >? X 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 id = \y0.1 + y0 0.00/0.02 0.00/0.02 Using this interpretation, the requirements translate to: 0.00/0.02 0.00/0.02 [[id(_x0)]] = 1 + x0 > x0 = [[_x0]] 0.00/0.02 0.00/0.02 We can thus remove the following rules: 0.00/0.02 0.00/0.02 id(X) => X 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