Certification Problem

Input (TPDB TRS_Innermost/Mixed_innermost/innermost4)

The rewrite relation of the following TRS is considered.

f(a(x),y,s(z),u) f(a(b),y,z,g(x,y,s(z),u)) (1)
g(x,y,z,u) h(x,y,z,u) (2)
h(b,y,z,u) f(y,y,z,u) (3)
a(b) c (4)
The evaluation strategy is innermost.

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#(a(x),y,s(z),u) f#(a(b),y,z,g(x,y,s(z),u)) (5)
f#(a(x),y,s(z),u) a#(b) (6)
f#(a(x),y,s(z),u) g#(x,y,s(z),u) (7)
g#(x,y,z,u) h#(x,y,z,u) (8)
h#(b,y,z,u) f#(y,y,z,u) (9)

1.1 Dependency Graph Processor

The dependency pairs are split into 1 component.