Certification Problem

Input (TPDB TRS_Standard/Transformed_CSR_04/Ex1_2_Luc02c_FR)

The rewrite relation of the following TRS is considered.

2nd(cons(X,n__cons(Y,Z))) activate(Y) (1)
from(X) cons(X,n__from(n__s(X))) (2)
cons(X1,X2) n__cons(X1,X2) (3)
from(X) n__from(X) (4)
s(X) n__s(X) (5)
activate(n__cons(X1,X2)) cons(activate(X1),X2) (6)
activate(n__from(X)) from(activate(X)) (7)
activate(n__s(X)) s(activate(X)) (8)
activate(X) X (9)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by ttt2 @ termCOMP 2023)

1 Rule Removal

Using the Weighted Path Order with the following precedence and status
prec(s) = 1 status(s) = [1] list-extension(s) = Lex
prec(n__from) = 0 status(n__from) = [1] list-extension(n__from) = Lex
prec(n__s) = 0 status(n__s) = [1] list-extension(n__s) = Lex
prec(from) = 3 status(from) = [1] list-extension(from) = Lex
prec(activate) = 7 status(activate) = [1] list-extension(activate) = Lex
prec(2nd) = 0 status(2nd) = [1] list-extension(2nd) = Lex
prec(cons) = 2 status(cons) = [1, 2] list-extension(cons) = Lex
prec(n__cons) = 0 status(n__cons) = [1, 2] list-extension(n__cons) = Lex
and the following Max-polynomial interpretation
[s(x1)] = max(0, 0 + 1 · x1)
[n__from(x1)] = max(0, 0 + 1 · x1)
[n__s(x1)] = max(0, 0 + 1 · x1)
[from(x1)] = max(0, 0 + 1 · x1)
[activate(x1)] = 0 + 1 · x1
[2nd(x1)] = max(0, 6 + 1 · x1)
[cons(x1, x2)] = max(0, 0 + 1 · x1, 0 + 1 · x2)
[n__cons(x1, x2)] = max(0, 0 + 1 · x1, 0 + 1 · x2)
all of the following rules can be deleted.
2nd(cons(X,n__cons(Y,Z))) activate(Y) (1)
from(X) cons(X,n__from(n__s(X))) (2)
cons(X1,X2) n__cons(X1,X2) (3)
from(X) n__from(X) (4)
s(X) n__s(X) (5)
activate(n__cons(X1,X2)) cons(activate(X1),X2) (6)
activate(n__from(X)) from(activate(X)) (7)
activate(n__s(X)) s(activate(X)) (8)
activate(X) X (9)

1.1 R is empty

There are no rules in the TRS. Hence, it is terminating.