Certification Problem

Input (TPDB TRS_Standard/SK90/2.40)

The rewrite relation of the following TRS is considered.

or(true,y) true (1)
or(x,true) true (2)
or(false,false) false (3)
mem(x,nil) false (4)
mem(x,set(y)) =(x,y) (5)
mem(x,union(y,z)) or(mem(x,y),mem(x,z)) (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.
mem#(x,union(y,z)) mem#(x,y) (7)
mem#(x,union(y,z)) mem#(x,z) (8)
mem#(x,union(y,z)) or#(mem(x,y),mem(x,z)) (9)

1.1 Dependency Graph Processor

The dependency pairs are split into 1 component.