Certification Problem

Input (TPDB TRS_Standard/Transformed_CSR_04/Ex3_12_Luc96a_FR)

The rewrite relation of the following TRS is considered.

from(X) cons(X,n__from(n__s(X))) (1)
sel(0,cons(X,Y)) X (2)
sel(s(X),cons(Y,Z)) sel(X,activate(Z)) (3)
from(X) n__from(X) (4)
s(X) n__s(X) (5)
activate(n__from(X)) from(activate(X)) (6)
activate(n__s(X)) s(activate(X)) (7)
activate(X) X (8)

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Rule Removal

Using the
prec(from) = 3 stat(from) = mul
prec(cons) = 0 stat(cons) = mul
prec(n__from) = 1 stat(n__from) = mul
prec(n__s) = 2 stat(n__s) = mul
prec(sel) = 6 stat(sel) = lex
prec(0) = 7 stat(0) = mul
prec(s) = 4 stat(s) = mul
prec(activate) = 5 stat(activate) = mul

π(from) = [1]
π(cons) = [1,2]
π(n__from) = [1]
π(n__s) = [1]
π(sel) = [1,2]
π(0) = []
π(s) = [1]
π(activate) = [1]

all of the following rules can be deleted.
from(X) cons(X,n__from(n__s(X))) (1)
sel(0,cons(X,Y)) X (2)
sel(s(X),cons(Y,Z)) sel(X,activate(Z)) (3)
from(X) n__from(X) (4)
s(X) n__s(X) (5)
activate(n__from(X)) from(activate(X)) (6)
activate(n__s(X)) s(activate(X)) (7)
activate(X) X (8)

1.1 R is empty

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