17.25/17.34 YES 17.35/17.37 We consider the system theBenchmark. 17.35/17.37 17.35/17.37 Alphabet: 17.35/17.37 17.35/17.37 cons : [d * e] --> e 17.35/17.37 g : [] --> b 17.35/17.37 map!fac62201 : [d -> d * e] --> e 17.35/17.37 map!fac62202 : [d -> a -> d * a * e] --> e 17.35/17.37 map!fac62203 : [b -> d -> c -> d * b * c * e] --> e 17.35/17.37 17.35/17.37 Rules: 17.35/17.37 17.35/17.37 map!fac62201(f, cons(x, y)) => cons(f x, map!fac62201(f, y)) 17.35/17.37 map!fac62202(f, x, cons(y, z)) => cons(f y x, map!fac62202(f, x, z)) 17.35/17.37 map!fac62203(f, g, x, cons(y, z)) => cons(f g y x, map!fac62203(f, g, x, z)) 17.35/17.37 17.35/17.37 This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). 17.35/17.37 17.35/17.37 We use rule removal, following [Kop12, Theorem 2.23]. 17.35/17.37 17.35/17.37 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 17.35/17.37 17.35/17.37 map!fac62201(F, cons(X, Y)) >? cons(F X, map!fac62201(F, Y)) 17.35/17.37 map!fac62202(F, X, cons(Y, Z)) >? cons(F Y X, map!fac62202(F, X, Z)) 17.35/17.37 map!fac62203(F, g, X, cons(Y, Z)) >? cons(F g Y X, map!fac62203(F, g, X, Z)) 17.35/17.37 17.35/17.37 We use a recursive path ordering as defined in [Kop12, Chapter 5]. 17.35/17.37 17.35/17.37 Argument functions: 17.35/17.37 17.35/17.37 [[g]] = _|_ 17.35/17.37 17.35/17.37 We choose Lex = {} and Mul = {@_{o -> o -> o -> o}, @_{o -> o -> o}, @_{o -> o}, cons, map!fac62201, map!fac62202, map!fac62203}, and the following precedence: map!fac62201 > map!fac62203 > @_{o -> o -> o} = map!fac62202 > @_{o -> o} > cons > @_{o -> o -> o -> o} 17.35/17.37 17.35/17.37 Taking the argument function into account, and fixing the greater / greater equal choices, the constraints can be denoted as follows: 17.35/17.37 17.35/17.37 map!fac62201(F, cons(X, Y)) > cons(@_{o -> o}(F, X), map!fac62201(F, Y)) 17.35/17.37 map!fac62202(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) 17.35/17.37 map!fac62203(F, _|_, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X), map!fac62203(F, _|_, X, Z)) 17.35/17.37 17.35/17.37 With these choices, we have: 17.35/17.37 17.35/17.37 1] map!fac62201(F, cons(X, Y)) > cons(@_{o -> o}(F, X), map!fac62201(F, Y)) because [2], by definition 17.35/17.37 2] map!fac62201*(F, cons(X, Y)) >= cons(@_{o -> o}(F, X), map!fac62201(F, Y)) because map!fac62201 > cons, [3] and [10], by (Copy) 17.35/17.37 3] map!fac62201*(F, cons(X, Y)) >= @_{o -> o}(F, X) because map!fac62201 > @_{o -> o}, [4] and [6], by (Copy) 17.35/17.37 4] map!fac62201*(F, cons(X, Y)) >= F because [5], by (Select) 17.35/17.37 5] F >= F by (Meta) 17.35/17.37 6] map!fac62201*(F, cons(X, Y)) >= X because [7], by (Select) 17.35/17.37 7] cons(X, Y) >= X because [8], by (Star) 17.35/17.37 8] cons*(X, Y) >= X because [9], by (Select) 17.35/17.37 9] X >= X by (Meta) 17.35/17.37 10] map!fac62201*(F, cons(X, Y)) >= map!fac62201(F, Y) because map!fac62201 in Mul, [11] and [12], by (Stat) 17.35/17.37 11] F >= F by (Meta) 17.35/17.37 12] cons(X, Y) > Y because [13], by definition 17.35/17.37 13] cons*(X, Y) >= Y because [14], by (Select) 17.35/17.37 14] Y >= Y by (Meta) 17.35/17.37 17.35/17.37 15] map!fac62202(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) because [16], by (Star) 17.35/17.37 16] map!fac62202*(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) because map!fac62202 > cons, [17] and [25], by (Copy) 17.35/17.37 17] map!fac62202*(F, X, cons(Y, Z)) >= @_{o -> o}(@_{o -> o -> o}(F, Y), X) because map!fac62202 > @_{o -> o}, [18] and [23], by (Copy) 17.35/17.37 18] map!fac62202*(F, X, cons(Y, Z)) >= @_{o -> o -> o}(F, Y) because map!fac62202 = @_{o -> o -> o}, map!fac62202 in Mul, [19] and [20], by (Stat) 17.35/17.37 19] F >= F by (Meta) 17.35/17.37 20] cons(Y, Z) > Y because [21], by definition 17.35/17.37 21] cons*(Y, Z) >= Y because [22], by (Select) 17.35/17.37 22] Y >= Y by (Meta) 17.35/17.37 23] map!fac62202*(F, X, cons(Y, Z)) >= X because [24], by (Select) 17.35/17.37 24] X >= X by (Meta) 17.35/17.37 25] map!fac62202*(F, X, cons(Y, Z)) >= map!fac62202(F, X, Z) because map!fac62202 in Mul, [19], [26] and [27], by (Stat) 17.35/17.37 26] X >= X by (Meta) 17.35/17.37 27] cons(Y, Z) > Z because [28], by definition 17.35/17.37 28] cons*(Y, Z) >= Z because [29], by (Select) 17.35/17.37 29] Z >= Z by (Meta) 17.35/17.37 17.35/17.37 30] map!fac62203(F, _|_, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X), map!fac62203(F, _|_, X, Z)) because [31], by (Star) 17.35/17.37 31] map!fac62203*(F, _|_, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X), map!fac62203(F, _|_, X, Z)) because map!fac62203 > cons, [32] and [44], by (Copy) 17.35/17.37 32] map!fac62203*(F, _|_, X, cons(Y, Z)) >= @_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X) because map!fac62203 > @_{o -> o}, [33] and [42], by (Copy) 17.35/17.37 33] map!fac62203*(F, _|_, X, cons(Y, Z)) >= @_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y) because map!fac62203 > @_{o -> o -> o}, [34] and [38], by (Copy) 17.35/17.37 34] map!fac62203*(F, _|_, X, cons(Y, Z)) >= @_{o -> o -> o -> o}(F, _|_) because map!fac62203 > @_{o -> o -> o -> o}, [35] and [37], by (Copy) 17.35/17.37 35] map!fac62203*(F, _|_, X, cons(Y, Z)) >= F because [36], by (Select) 17.35/17.37 36] F >= F by (Meta) 17.35/17.37 37] map!fac62203*(F, _|_, X, cons(Y, Z)) >= _|_ by (Bot) 17.35/17.37 38] map!fac62203*(F, _|_, X, cons(Y, Z)) >= Y because [39], by (Select) 17.35/17.37 39] cons(Y, Z) >= Y because [40], by (Star) 17.35/17.37 40] cons*(Y, Z) >= Y because [41], by (Select) 17.35/17.37 41] Y >= Y by (Meta) 17.35/17.37 42] map!fac62203*(F, _|_, X, cons(Y, Z)) >= X because [43], by (Select) 17.35/17.37 43] X >= X by (Meta) 17.35/17.37 44] map!fac62203*(F, _|_, X, cons(Y, Z)) >= map!fac62203(F, _|_, X, Z) because map!fac62203 in Mul, [45], [46], [47] and [48], by (Stat) 17.35/17.37 45] F >= F by (Meta) 17.35/17.37 46] _|_ >= _|_ by (Bot) 17.35/17.37 47] X >= X by (Meta) 17.35/17.37 48] cons(Y, Z) > Z because [49], by definition 17.35/17.37 49] cons*(Y, Z) >= Z because [50], by (Select) 17.35/17.37 50] Z >= Z by (Meta) 17.35/17.37 17.35/17.37 We can thus remove the following rules: 17.35/17.37 17.35/17.37 map!fac62201(F, cons(X, Y)) => cons(F X, map!fac62201(F, Y)) 17.35/17.37 17.35/17.37 We use rule removal, following [Kop12, Theorem 2.23]. 17.35/17.37 17.35/17.37 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 17.35/17.37 17.35/17.37 map!fac62202(F, X, cons(Y, Z)) >? cons(F Y X, map!fac62202(F, X, Z)) 17.35/17.37 map!fac62203(F, g, X, cons(Y, Z)) >? cons(F g Y X, map!fac62203(F, g, X, Z)) 17.35/17.37 17.35/17.37 We use a recursive path ordering as defined in [Kop12, Chapter 5]. 17.35/17.37 17.35/17.37 Argument functions: 17.35/17.37 17.35/17.37 [[g]] = _|_ 17.35/17.37 17.35/17.37 We choose Lex = {} and Mul = {@_{o -> o -> o -> o}, @_{o -> o -> o}, @_{o -> o}, cons, map!fac62202, map!fac62203}, and the following precedence: map!fac62202 > @_{o -> o -> o -> o} = map!fac62203 > @_{o -> o -> o} > @_{o -> o} > cons 17.35/17.37 17.35/17.37 Taking the argument function into account, and fixing the greater / greater equal choices, the constraints can be denoted as follows: 17.35/17.37 17.35/17.37 map!fac62202(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) 17.35/17.37 map!fac62203(F, _|_, X, cons(Y, Z)) > cons(@_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X), map!fac62203(F, _|_, X, Z)) 17.35/17.37 17.35/17.37 With these choices, we have: 17.35/17.37 17.35/17.37 1] map!fac62202(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) because [2], by (Star) 17.35/17.37 2] map!fac62202*(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) because map!fac62202 > cons, [3] and [13], by (Copy) 17.35/17.37 3] map!fac62202*(F, X, cons(Y, Z)) >= @_{o -> o}(@_{o -> o -> o}(F, Y), X) because map!fac62202 > @_{o -> o}, [4] and [11], by (Copy) 17.35/17.37 4] map!fac62202*(F, X, cons(Y, Z)) >= @_{o -> o -> o}(F, Y) because map!fac62202 > @_{o -> o -> o}, [5] and [7], by (Copy) 17.35/17.37 5] map!fac62202*(F, X, cons(Y, Z)) >= F because [6], by (Select) 17.35/17.37 6] F >= F by (Meta) 17.35/17.37 7] map!fac62202*(F, X, cons(Y, Z)) >= Y because [8], by (Select) 17.35/17.37 8] cons(Y, Z) >= Y because [9], by (Star) 17.35/17.37 9] cons*(Y, Z) >= Y because [10], by (Select) 17.35/17.37 10] Y >= Y by (Meta) 17.35/17.37 11] map!fac62202*(F, X, cons(Y, Z)) >= X because [12], by (Select) 17.35/17.37 12] X >= X by (Meta) 17.35/17.37 13] map!fac62202*(F, X, cons(Y, Z)) >= map!fac62202(F, X, Z) because map!fac62202 in Mul, [14], [15] and [16], by (Stat) 17.35/17.37 14] F >= F by (Meta) 17.35/17.37 15] X >= X by (Meta) 17.35/17.37 16] cons(Y, Z) > Z because [17], by definition 17.35/17.37 17] cons*(Y, Z) >= Z because [18], by (Select) 17.35/17.37 18] Z >= Z by (Meta) 17.35/17.37 17.35/17.37 19] map!fac62203(F, _|_, X, cons(Y, Z)) > cons(@_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X), map!fac62203(F, _|_, X, Z)) because [20], by definition 17.35/17.37 20] map!fac62203*(F, _|_, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X), map!fac62203(F, _|_, X, Z)) because map!fac62203 > cons, [21] and [32], by (Copy) 17.35/17.37 21] map!fac62203*(F, _|_, X, cons(Y, Z)) >= @_{o -> o}(@_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y), X) because map!fac62203 > @_{o -> o}, [22] and [30], by (Copy) 17.35/17.37 22] map!fac62203*(F, _|_, X, cons(Y, Z)) >= @_{o -> o -> o}(@_{o -> o -> o -> o}(F, _|_), Y) because map!fac62203 > @_{o -> o -> o}, [23] and [26], by (Copy) 17.35/17.37 23] map!fac62203*(F, _|_, X, cons(Y, Z)) >= @_{o -> o -> o -> o}(F, _|_) because map!fac62203 = @_{o -> o -> o -> o}, map!fac62203 in Mul, [24] and [25], by (Stat) 17.35/17.37 24] F >= F by (Meta) 17.35/17.37 25] X >= _|_ by (Bot) 17.35/17.37 26] map!fac62203*(F, _|_, X, cons(Y, Z)) >= Y because [27], by (Select) 17.35/17.37 27] cons(Y, Z) >= Y because [28], by (Star) 17.35/17.37 28] cons*(Y, Z) >= Y because [29], by (Select) 17.35/17.37 29] Y >= Y by (Meta) 17.35/17.37 30] map!fac62203*(F, _|_, X, cons(Y, Z)) >= X because [31], by (Select) 17.35/17.37 31] X >= X by (Meta) 17.35/17.37 32] map!fac62203*(F, _|_, X, cons(Y, Z)) >= map!fac62203(F, _|_, X, Z) because map!fac62203 in Mul, [24], [33], [34] and [35], by (Stat) 17.35/17.37 33] _|_ >= _|_ by (Bot) 17.35/17.37 34] X >= X by (Meta) 17.35/17.37 35] cons(Y, Z) > Z because [36], by definition 17.35/17.37 36] cons*(Y, Z) >= Z because [37], by (Select) 17.35/17.37 37] Z >= Z by (Meta) 17.35/17.37 17.35/17.37 We can thus remove the following rules: 17.35/17.37 17.35/17.37 map!fac62203(F, g, X, cons(Y, Z)) => cons(F g Y X, map!fac62203(F, g, X, Z)) 17.35/17.37 17.35/17.37 We use rule removal, following [Kop12, Theorem 2.23]. 17.35/17.37 17.35/17.37 This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): 17.35/17.37 17.35/17.37 map!fac62202(F, X, cons(Y, Z)) >? cons(F Y X, map!fac62202(F, X, Z)) 17.35/17.37 17.35/17.37 We use a recursive path ordering as defined in [Kop12, Chapter 5]. 17.35/17.37 17.35/17.37 We choose Lex = {} and Mul = {@_{o -> o -> o}, @_{o -> o}, cons, map!fac62202}, and the following precedence: @_{o -> o -> o} = map!fac62202 > @_{o -> o} > cons 17.35/17.37 17.35/17.37 With these choices, we have: 17.35/17.37 17.35/17.37 1] map!fac62202(F, X, cons(Y, Z)) > cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) because [2], by definition 17.35/17.37 2] map!fac62202*(F, X, cons(Y, Z)) >= cons(@_{o -> o}(@_{o -> o -> o}(F, Y), X), map!fac62202(F, X, Z)) because map!fac62202 > cons, [3] and [11], by (Copy) 17.35/17.37 3] map!fac62202*(F, X, cons(Y, Z)) >= @_{o -> o}(@_{o -> o -> o}(F, Y), X) because map!fac62202 > @_{o -> o}, [4] and [9], by (Copy) 17.35/17.37 4] map!fac62202*(F, X, cons(Y, Z)) >= @_{o -> o -> o}(F, Y) because map!fac62202 = @_{o -> o -> o}, map!fac62202 in Mul, [5] and [6], by (Stat) 17.35/17.37 5] F >= F by (Meta) 17.35/17.37 6] cons(Y, Z) > Y because [7], by definition 17.35/17.37 7] cons*(Y, Z) >= Y because [8], by (Select) 17.35/17.37 8] Y >= Y by (Meta) 17.35/17.37 9] map!fac62202*(F, X, cons(Y, Z)) >= X because [10], by (Select) 17.35/17.37 10] X >= X by (Meta) 17.35/17.37 11] map!fac62202*(F, X, cons(Y, Z)) >= map!fac62202(F, X, Z) because map!fac62202 in Mul, [5], [12] and [13], by (Stat) 17.35/17.37 12] X >= X by (Meta) 17.35/17.37 13] cons(Y, Z) > Z because [14], by definition 17.35/17.37 14] cons*(Y, Z) >= Z because [15], by (Select) 17.35/17.37 15] Z >= Z by (Meta) 17.35/17.37 17.35/17.37 We can thus remove the following rules: 17.35/17.37 17.35/17.37 map!fac62202(F, X, cons(Y, Z)) => cons(F Y X, map!fac62202(F, X, Z)) 17.35/17.37 17.35/17.37 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. 17.35/17.37 17.35/17.37 17.35/17.37 +++ Citations +++ 17.35/17.37 17.35/17.37 [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. 17.35/17.38 EOF