Certification Problem

Input (TPDB TRS_Standard/SK90/2.13)

The rewrite relation of the following TRS is considered.

double(0) 0 (1)
double(s(x)) s(s(double(x))) (2)
+(x,0) x (3)
+(x,s(y)) s(+(x,y)) (4)
+(s(x),y) s(+(x,y)) (5)
double(x) +(x,x) (6)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by NaTT @ termCOMP 2023)

1 Dependency Pair Transformation

The following set of initial dependency pairs has been identified.
double#(x) +#(x,x) (7)
+#(s(x),y) +#(x,y) (8)
double#(s(x)) double#(x) (9)
+#(x,s(y)) +#(x,y) (10)

1.1 Dependency Graph Processor

The dependency pairs are split into 2 components.