0.00/0.05 YES 0.00/0.05 We consider the system theBenchmark. 0.00/0.05 0.00/0.05 Alphabet: 0.00/0.05 0.00/0.05 f : [N -> N * N] --> N 0.00/0.05 g : [] --> N -> N 0.00/0.05 h : [N] --> N 0.00/0.05 0.00/0.05 Rules: 0.00/0.05 0.00/0.05 f(g, x) => h(x) 0.00/0.05 f(i, x) => i x 0.00/0.05 h(x) => f(/\y.y, x) 0.00/0.05 0.00/0.05 This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). 0.00/0.05 0.00/0.05 We use rule removal, following [Kop12, Theorem 2.23]. 0.00/0.05 0.00/0.05 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 0.00/0.05 0.00/0.05 f(g, X) >? h(X) 0.00/0.05 f(F, X) >? F X 0.00/0.05 h(X) >? f(/\x.x, X) 0.00/0.05 0.00/0.05 We orient these requirements with a polynomial interpretation in the natural numbers. 0.00/0.05 0.00/0.05 The following interpretation satisfies the requirements: 0.00/0.05 0.00/0.05 f = \G0y1.y1 + 2G0(y1) 0.00/0.05 g = \y0.3 + 3y0 0.00/0.05 h = \y0.3y0 0.00/0.05 0.00/0.05 Using this interpretation, the requirements translate to: 0.00/0.05 0.00/0.05 [[f(g, _x0)]] = 6 + 7x0 > 3x0 = [[h(_x0)]] 0.00/0.05 [[f(_F0, _x1)]] = x1 + 2F0(x1) >= x1 + F0(x1) = [[_F0 _x1]] 0.00/0.05 [[h(_x0)]] = 3x0 >= 3x0 = [[f(/\x.x, _x0)]] 0.00/0.05 0.00/0.05 We can thus remove the following rules: 0.00/0.05 0.00/0.05 f(g, X) => h(X) 0.00/0.05 0.00/0.05 We use rule removal, following [Kop12, Theorem 2.23]. 0.00/0.05 0.00/0.05 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 0.00/0.05 0.00/0.05 f(F, X) >? F X 0.00/0.05 h(X) >? f(/\x.x, X) 0.00/0.05 0.00/0.05 We orient these requirements with a polynomial interpretation in the natural numbers. 0.00/0.05 0.00/0.05 The following interpretation satisfies the requirements: 0.00/0.05 0.00/0.05 f = \G0y1.y1 + G0(y1) 0.00/0.05 h = \y0.3 + 3y0 0.00/0.05 0.00/0.05 Using this interpretation, the requirements translate to: 0.00/0.05 0.00/0.05 [[f(_F0, _x1)]] = x1 + F0(x1) >= x1 + F0(x1) = [[_F0 _x1]] 0.00/0.05 [[h(_x0)]] = 3 + 3x0 > 2x0 = [[f(/\x.x, _x0)]] 0.00/0.05 0.00/0.05 We can thus remove the following rules: 0.00/0.05 0.00/0.05 h(X) => f(/\x.x, X) 0.00/0.05 0.00/0.05 We use rule removal, following [Kop12, Theorem 2.23]. 0.00/0.05 0.00/0.05 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 0.00/0.05 0.00/0.05 f(F, X) >? F X 0.00/0.05 0.00/0.05 We orient these requirements with a polynomial interpretation in the natural numbers. 0.00/0.05 0.00/0.05 The following interpretation satisfies the requirements: 0.00/0.05 0.00/0.05 f = \G0y1.1 + y1 + G0(y1) 0.00/0.05 0.00/0.05 Using this interpretation, the requirements translate to: 0.00/0.05 0.00/0.05 [[f(_F0, _x1)]] = 1 + x1 + F0(x1) > x1 + F0(x1) = [[_F0 _x1]] 0.00/0.05 0.00/0.05 We can thus remove the following rules: 0.00/0.05 0.00/0.05 f(F, X) => F X 0.00/0.05 0.00/0.05 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. 0.00/0.05 0.00/0.05 0.00/0.05 +++ Citations +++ 0.00/0.05 0.00/0.05 [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. 0.00/0.05 EOF