0.00/0.53 YES 0.00/0.54 We consider the system theBenchmark. 0.00/0.54 0.00/0.54 Alphabet: 0.00/0.54 0.00/0.54 0 : [] --> ord 0.00/0.54 lim : [nat -> ord] --> ord 0.00/0.54 rec : [ord * a * ord -> a -> a * (nat -> ord) -> (nat -> a) -> a] --> a 0.00/0.54 s : [ord] --> ord 0.00/0.54 0.00/0.54 Rules: 0.00/0.54 0.00/0.54 rec(0, x, f, g) => x 0.00/0.54 rec(s(x), y, f, g) => f x rec(x, y, f, g) 0.00/0.54 rec(lim(f), x, g, h) => h f (/\y.rec(f y, x, g, h)) 0.00/0.54 0.00/0.54 This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). 0.00/0.54 0.00/0.54 We use the dependency pair framework as described in [Kop12, Ch. 6/7], with static dependency pairs (see [KusIsoSakBla09] and the adaptation for AFSMs and accessible arguments in [Kop13]). 0.00/0.54 0.00/0.54 We thus obtain the following dependency pair problem (P_0, R_0, static, formative): 0.00/0.54 0.00/0.54 Dependency Pairs P_0: 0.00/0.54 0.00/0.54 0] rec#(s(X), Y, F, G) =#> rec#(X, Y, F, G) 0.00/0.54 1] rec#(lim(F), X, G, H) =#> rec#(F Y, X, G, H) 0.00/0.54 0.00/0.54 Rules R_0: 0.00/0.54 0.00/0.54 rec(0, X, F, G) => X 0.00/0.54 rec(s(X), Y, F, G) => F X rec(X, Y, F, G) 0.00/0.54 rec(lim(F), X, G, H) => H F (/\x.rec(F x, X, G, H)) 0.00/0.54 0.00/0.54 Thus, the original system is terminating if (P_0, R_0, static, formative) is finite. 0.00/0.54 0.00/0.54 We consider the dependency pair problem (P_0, R_0, static, formative). 0.00/0.54 0.00/0.54 We apply the accessible subterm criterion with the following projection function: 0.00/0.54 0.00/0.54 nu(rec#) = 1 0.00/0.54 0.00/0.54 Thus, we can orient the dependency pairs as follows: 0.00/0.54 0.00/0.54 nu(rec#(s(X), Y, F, G)) = s(X) [>] X = nu(rec#(X, Y, F, G)) 0.00/0.54 nu(rec#(lim(F), X, G, H)) = lim(F) [>] F Y = nu(rec#(F Y, X, G, H)) 0.00/0.54 0.00/0.54 By [Kop13, Thm. 6], we may replace a dependency pair problem (P_0, R_0, static, f) by ({}, R_0, static, f). By the empty set processor [Kop12, Thm. 7.15] this problem may be immediately removed. 0.00/0.54 0.00/0.54 As all dependency pair problems were succesfully simplified with sound (and complete) processors until nothing remained, we conclude termination. 0.00/0.54 0.00/0.54 0.00/0.54 +++ Citations +++ 0.00/0.54 0.00/0.54 [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. 0.00/0.54 [Kop13] C. Kop. Static Dependency Pairs with Accessibility. Unpublished manuscript, http://cl-informatik.uibk.ac.at/users/kop/static.pdf, 2013. 0.00/0.54 [KusIsoSakBla09] K. Kusakari, Y. Isogai, M. Sakai, and F. Blanqui. Static Dependency Pair Method Based On Strong Computability for Higher-Order Rewrite Systems. In volume 92(10) of IEICE Transactions on Information and Systems. 2007--2015, 2009. 0.00/0.54 EOF