Certification Problem

Input (TPDB TRS_Innermost/Transformed_CSR_innermost_04/Ex6_Luc98_L)

The rewrite relation of the following TRS is considered.

first(0,X) nil (1)
first(s(X),cons(Y)) cons(Y) (2)
from(X) cons(X) (3)
The evaluation strategy is innermost.

Property / Task

Prove or disprove termination.

Answer / Result

Yes.

Proof (by AProVE @ termCOMP 2023)

1 Rule Removal

Using the Knuth Bendix order with w0 = 1 and the following precedence and weight functions
prec(0) = 0 weight(0) = 1
prec(nil) = 1 weight(nil) = 2
prec(s) = 2 weight(s) = 1
prec(cons) = 3 weight(cons) = 1
prec(from) = 4 weight(from) = 1
prec(first) = 5 weight(first) = 0
all of the following rules can be deleted.
first(0,X) nil (1)
first(s(X),cons(Y)) cons(Y) (2)
from(X) cons(X) (3)

1.1 R is empty

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