0.00/0.03 YES 0.00/0.03 We consider the system theBenchmark. 0.00/0.03 0.00/0.03 Alphabet: 0.00/0.03 0.00/0.03 fapp : [o * o] --> o 0.00/0.03 h : [o] --> o 0.00/0.03 lam : [o -> o] --> o 0.00/0.03 0.00/0.03 Rules: 0.00/0.03 0.00/0.03 fapp(lam(f), x) => f h(x) 0.00/0.03 0.00/0.03 This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). 0.00/0.03 0.00/0.03 We use the dependency pair framework as described in [Kop12, Ch. 6/7], with dynamic dependency pairs. 0.00/0.03 0.00/0.03 After applying [Kop12, Thm. 7.22] to denote collapsing dependency pairs in an extended form, we thus obtain the following dependency pair problem (P_0, R_0, minimal, formative): 0.00/0.03 0.00/0.03 Dependency Pairs P_0: 0.00/0.03 0.00/0.03 0] fapp#(lam(F), X) =#> F(h(X)) 0.00/0.03 0.00/0.03 Rules R_0: 0.00/0.03 0.00/0.03 fapp(lam(F), X) => F h(X) 0.00/0.03 0.00/0.03 Thus, the original system is terminating if (P_0, R_0, minimal, formative) is finite. 0.00/0.03 0.00/0.03 We consider the dependency pair problem (P_0, R_0, minimal, formative). 0.00/0.03 0.00/0.03 We will use the reduction pair processor [Kop12, Thm. 7.16]. As the system is abstraction-simple and the formative flag is set, it suffices to find a tagged reduction pair [Kop12, Def. 6.70]. Thus, we must orient: 0.00/0.03 0.00/0.03 fapp#(lam(F), X) >? F(h(X)) 0.00/0.03 fapp(lam(F), X) >= F h(X) 0.00/0.03 0.00/0.03 We orient these requirements with a polynomial interpretation in the natural numbers. 0.00/0.03 0.00/0.03 The following interpretation satisfies the requirements: 0.00/0.03 0.00/0.03 fapp = \y0y1.3 + 3y0 0.00/0.03 fapp# = \y0y1.3 + y0 0.00/0.03 h = \y0.0 0.00/0.03 lam = \G0.3 + G0(0) 0.00/0.03 0.00/0.03 Using this interpretation, the requirements translate to: 0.00/0.03 0.00/0.03 [[fapp#(lam(_F0), _x1)]] = 6 + F0(0) > F0(0) = [[_F0(h(_x1))]] 0.00/0.03 [[fapp(lam(_F0), _x1)]] = 12 + 3F0(0) >= F0(0) = [[_F0 h(_x1)]] 0.00/0.03 0.00/0.03 By the observations in [Kop12, Sec. 6.6], this reduction pair suffices; we may thus replace a dependency pair problem (P_0, R_0) by ({}, R_0). By the empty set processor [Kop12, Thm. 7.15] this problem may be immediately removed. 0.00/0.03 0.00/0.03 As all dependency pair problems were succesfully simplified with sound (and complete) processors until nothing remained, we conclude termination. 0.00/0.03 0.00/0.03 0.00/0.03 +++ Citations +++ 0.00/0.03 0.00/0.03 [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. 0.00/0.03 EOF