Certification Problem

Input (TPDB TRS_Standard/Transformed_CSR_04/Ex26_Luc03b_Z)

The rewrite relation of the following TRS is considered.

terms(N) cons(recip(sqr(N)),n__terms(s(N))) (1)
sqr(0) 0 (2)
sqr(s(X)) s(n__add(sqr(activate(X)),dbl(activate(X)))) (3)
dbl(0) 0 (4)
dbl(s(X)) s(n__s(n__dbl(activate(X)))) (5)
add(0,X) X (6)
add(s(X),Y) s(n__add(activate(X),Y)) (7)
first(0,X) nil (8)
first(s(X),cons(Y,Z)) cons(Y,n__first(activate(X),activate(Z))) (9)
terms(X) n__terms(X) (10)
add(X1,X2) n__add(X1,X2) (11)
s(X) n__s(X) (12)
dbl(X) n__dbl(X) (13)
first(X1,X2) n__first(X1,X2) (14)
activate(n__terms(X)) terms(X) (15)
activate(n__add(X1,X2)) add(X1,X2) (16)
activate(n__s(X)) s(X) (17)
activate(n__dbl(X)) dbl(X) (18)
activate(n__first(X1,X2)) first(X1,X2) (19)
activate(X) X (20)

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.
first#(s(X),cons(Y,Z)) activate#(Z) (21)
dbl#(s(X)) activate#(X) (22)
sqr#(s(X)) dbl#(activate(X)) (23)
activate#(n__add(X1,X2)) add#(X1,X2) (24)
sqr#(s(X)) sqr#(activate(X)) (25)
sqr#(s(X)) activate#(X) (26)
sqr#(s(X)) activate#(X) (26)
activate#(n__s(X)) s#(X) (27)
sqr#(s(X)) s#(n__add(sqr(activate(X)),dbl(activate(X)))) (28)
dbl#(s(X)) s#(n__s(n__dbl(activate(X)))) (29)
activate#(n__terms(X)) terms#(X) (30)
terms#(N) s#(N) (31)
add#(s(X),Y) s#(n__add(activate(X),Y)) (32)
first#(s(X),cons(Y,Z)) activate#(X) (33)
activate#(n__first(X1,X2)) first#(X1,X2) (34)
terms#(N) sqr#(N) (35)
add#(s(X),Y) activate#(X) (36)
activate#(n__dbl(X)) dbl#(X) (37)

1.1 Dependency Graph Processor

The dependency pairs are split into 1 component.