Certification Problem

Input (TPDB TRS_Standard/Endrullis_06/labeling)

The rewrite relation of the following TRS is considered.

f(f(x,y,a),z,w) f(z,w,f(y,x,z)) (1)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
f#(f(x,y,a),z,w) f#(z,w,f(y,x,z)) (2)
f#(f(x,y,a),z,w) f#(y,x,z) (3)

1.1 Forward Instantiation Processor

We instantiate the pair to the following set of pairs
f#(f(x0,x1,a),f(y_0,y_1,a),x3) f#(f(y_0,y_1,a),x3,f(x1,x0,f(y_0,y_1,a))) (4)

1.1.1 Forward Instantiation Processor

We instantiate the pair to the following set of pairs
f#(f(x0,f(y_0,y_1,a),a),x2,x3) f#(f(y_0,y_1,a),x0,x2) (5)
f#(f(f(y_2,y_3,a),f(y_0,y_1,a),a),x2,x3) f#(f(y_0,y_1,a),f(y_2,y_3,a),x2) (6)

1.1.1.1 Semantic Labeling Processor

The following interpretations form a model of the rules.

As carrier we take the set {0,1}. Symbols are labeled by the interpretation of their arguments using the interpretations (modulo 2):

[a] = 1
[f(x1, x2, x3)] = 0
[f#(x1, x2, x3)] = 0

We obtain the set of labeled pairs

There are 128 ruless (increase limit for explicit display).

and the set of labeled rules:
f000(f001(x,y,a),z,w) f000(z,w,f000(y,x,z)) (135)
f001(f001(x,y,a),z,w) f010(z,w,f000(y,x,z)) (136)
f010(f001(x,y,a),z,w) f100(z,w,f001(y,x,z)) (137)
f011(f001(x,y,a),z,w) f110(z,w,f001(y,x,z)) (138)
f000(f011(x,y,a),z,w) f000(z,w,f100(y,x,z)) (139)
f001(f011(x,y,a),z,w) f010(z,w,f100(y,x,z)) (140)
f010(f011(x,y,a),z,w) f100(z,w,f101(y,x,z)) (141)
f011(f011(x,y,a),z,w) f110(z,w,f101(y,x,z)) (142)
f000(f101(x,y,a),z,w) f000(z,w,f010(y,x,z)) (143)
f001(f101(x,y,a),z,w) f010(z,w,f010(y,x,z)) (144)
f010(f101(x,y,a),z,w) f100(z,w,f011(y,x,z)) (145)
f011(f101(x,y,a),z,w) f110(z,w,f011(y,x,z)) (146)
f000(f111(x,y,a),z,w) f000(z,w,f110(y,x,z)) (147)
f001(f111(x,y,a),z,w) f010(z,w,f110(y,x,z)) (148)
f010(f111(x,y,a),z,w) f100(z,w,f111(y,x,z)) (149)
f011(f111(x,y,a),z,w) f110(z,w,f111(y,x,z)) (150)

1.1.1.1.1 Dependency Graph Processor

The dependency pairs are split into 1 component.