Certification Problem

Input (TPDB TRS_Standard/Transformed_CSR_04/Ex14_AEGL02_GM)

The rewrite relation of the following TRS is considered.

a__from(X) cons(mark(X),from(s(X))) (1)
a__length(nil) 0 (2)
a__length(cons(X,Y)) s(a__length1(Y)) (3)
a__length1(X) a__length(X) (4)
mark(from(X)) a__from(mark(X)) (5)
mark(length(X)) a__length(X) (6)
mark(length1(X)) a__length1(X) (7)
mark(cons(X1,X2)) cons(mark(X1),X2) (8)
mark(s(X)) s(mark(X)) (9)
mark(nil) nil (10)
mark(0) 0 (11)
a__from(X) from(X) (12)
a__length(X) length(X) (13)
a__length1(X) length1(X) (14)

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.
mark#(s(X)) mark#(X) (15)
a__length#(cons(X,Y)) a__length1#(Y) (16)
a__length1#(X) a__length#(X) (17)
a__from#(X) mark#(X) (18)
mark#(from(X)) mark#(X) (19)
mark#(length1(X)) a__length1#(X) (20)
mark#(length(X)) a__length#(X) (21)
mark#(cons(X1,X2)) mark#(X1) (22)
mark#(from(X)) a__from#(mark(X)) (23)

1.1 Dependency Graph Processor

The dependency pairs are split into 2 components.