Certification Problem

Input (TPDB TRS_Standard/Rubio_04/bintrees)

The rewrite relation of the following TRS is considered.

concat(leaf,Y) Y (1)
concat(cons(U,V),Y) cons(U,concat(V,Y)) (2)
lessleaves(X,leaf) false (3)
lessleaves(leaf,cons(W,Z)) true (4)
lessleaves(cons(U,V),cons(W,Z)) lessleaves(concat(U,V),concat(W,Z)) (5)

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.
lessleaves#(cons(U,V),cons(W,Z)) lessleaves#(concat(U,V),concat(W,Z)) (6)
lessleaves#(cons(U,V),cons(W,Z)) concat#(U,V) (7)
concat#(cons(U,V),Y) concat#(V,Y) (8)
lessleaves#(cons(U,V),cons(W,Z)) concat#(W,Z) (9)

1.1 Dependency Graph Processor

The dependency pairs are split into 2 components.