Term Rewriting System R:
[X, Y, X1, X2]
from(X) -> cons(X, nfrom(s(X)))
from(X) -> nfrom(X)
length(nnil) -> 0
length(ncons(X, Y)) -> s(length1(activate(Y)))
length1(X) -> length(activate(X))
nil -> nnil
cons(X1, X2) -> ncons(X1, X2)
activate(nfrom(X)) -> from(X)
activate(nnil) -> nil
activate(ncons(X1, X2)) -> cons(X1, X2)
activate(X) -> X

Termination of R to be shown.



   R
Dependency Pair Analysis



R contains the following Dependency Pairs:

FROM(X) -> CONS(X, nfrom(s(X)))
LENGTH(ncons(X, Y)) -> LENGTH1(activate(Y))
LENGTH(ncons(X, Y)) -> ACTIVATE(Y)
LENGTH1(X) -> LENGTH(activate(X))
LENGTH1(X) -> ACTIVATE(X)
ACTIVATE(nfrom(X)) -> FROM(X)
ACTIVATE(nnil) -> NIL
ACTIVATE(ncons(X1, X2)) -> CONS(X1, X2)

Furthermore, R contains one SCC.


   R
DPs
       →DP Problem 1
Narrowing Transformation


Dependency Pairs:

LENGTH1(X) -> LENGTH(activate(X))
LENGTH(ncons(X, Y)) -> LENGTH1(activate(Y))


Rules:


from(X) -> cons(X, nfrom(s(X)))
from(X) -> nfrom(X)
length(nnil) -> 0
length(ncons(X, Y)) -> s(length1(activate(Y)))
length1(X) -> length(activate(X))
nil -> nnil
cons(X1, X2) -> ncons(X1, X2)
activate(nfrom(X)) -> from(X)
activate(nnil) -> nil
activate(ncons(X1, X2)) -> cons(X1, X2)
activate(X) -> X





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

LENGTH1(X) -> LENGTH(activate(X))
four new Dependency Pairs are created:

LENGTH1(nfrom(X'')) -> LENGTH(from(X''))
LENGTH1(nnil) -> LENGTH(nil)
LENGTH1(ncons(X1', X2')) -> LENGTH(cons(X1', X2'))
LENGTH1(X'') -> LENGTH(X'')

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Narrowing Transformation


Dependency Pairs:

LENGTH1(X'') -> LENGTH(X'')
LENGTH1(ncons(X1', X2')) -> LENGTH(cons(X1', X2'))
LENGTH1(nnil) -> LENGTH(nil)
LENGTH1(nfrom(X'')) -> LENGTH(from(X''))
LENGTH(ncons(X, Y)) -> LENGTH1(activate(Y))


Rules:


from(X) -> cons(X, nfrom(s(X)))
from(X) -> nfrom(X)
length(nnil) -> 0
length(ncons(X, Y)) -> s(length1(activate(Y)))
length1(X) -> length(activate(X))
nil -> nnil
cons(X1, X2) -> ncons(X1, X2)
activate(nfrom(X)) -> from(X)
activate(nnil) -> nil
activate(ncons(X1, X2)) -> cons(X1, X2)
activate(X) -> X





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

LENGTH1(nfrom(X'')) -> LENGTH(from(X''))
two new Dependency Pairs are created:

LENGTH1(nfrom(X''')) -> LENGTH(cons(X''', nfrom(s(X'''))))
LENGTH1(nfrom(X''')) -> LENGTH(nfrom(X'''))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 3
Narrowing Transformation


Dependency Pairs:

LENGTH1(nfrom(X''')) -> LENGTH(cons(X''', nfrom(s(X'''))))
LENGTH1(ncons(X1', X2')) -> LENGTH(cons(X1', X2'))
LENGTH1(nnil) -> LENGTH(nil)
LENGTH(ncons(X, Y)) -> LENGTH1(activate(Y))
LENGTH1(X'') -> LENGTH(X'')


Rules:


from(X) -> cons(X, nfrom(s(X)))
from(X) -> nfrom(X)
length(nnil) -> 0
length(ncons(X, Y)) -> s(length1(activate(Y)))
length1(X) -> length(activate(X))
nil -> nnil
cons(X1, X2) -> ncons(X1, X2)
activate(nfrom(X)) -> from(X)
activate(nnil) -> nil
activate(ncons(X1, X2)) -> cons(X1, X2)
activate(X) -> X





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

LENGTH1(nnil) -> LENGTH(nil)
one new Dependency Pair is created:

LENGTH1(nnil) -> LENGTH(nnil)

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 4
Narrowing Transformation


Dependency Pairs:

LENGTH1(X'') -> LENGTH(X'')
LENGTH1(ncons(X1', X2')) -> LENGTH(cons(X1', X2'))
LENGTH(ncons(X, Y)) -> LENGTH1(activate(Y))
LENGTH1(nfrom(X''')) -> LENGTH(cons(X''', nfrom(s(X'''))))


Rules:


from(X) -> cons(X, nfrom(s(X)))
from(X) -> nfrom(X)
length(nnil) -> 0
length(ncons(X, Y)) -> s(length1(activate(Y)))
length1(X) -> length(activate(X))
nil -> nnil
cons(X1, X2) -> ncons(X1, X2)
activate(nfrom(X)) -> from(X)
activate(nnil) -> nil
activate(ncons(X1, X2)) -> cons(X1, X2)
activate(X) -> X





On this DP problem, a Narrowing SCC transformation can be performed.
As a result of transforming the rule

LENGTH1(ncons(X1', X2')) -> LENGTH(cons(X1', X2'))
one new Dependency Pair is created:

LENGTH1(ncons(X1'', X2'')) -> LENGTH(ncons(X1'', X2''))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
Nar
           →DP Problem 2
Nar
             ...
               →DP Problem 5
Remaining Obligation(s)




The following remains to be proven:
Dependency Pairs:

LENGTH1(ncons(X1'', X2'')) -> LENGTH(ncons(X1'', X2''))
LENGTH1(nfrom(X''')) -> LENGTH(cons(X''', nfrom(s(X'''))))
LENGTH(ncons(X, Y)) -> LENGTH1(activate(Y))
LENGTH1(X'') -> LENGTH(X'')


Rules:


from(X) -> cons(X, nfrom(s(X)))
from(X) -> nfrom(X)
length(nnil) -> 0
length(ncons(X, Y)) -> s(length1(activate(Y)))
length1(X) -> length(activate(X))
nil -> nnil
cons(X1, X2) -> ncons(X1, X2)
activate(nfrom(X)) -> from(X)
activate(nnil) -> nil
activate(ncons(X1, X2)) -> cons(X1, X2)
activate(X) -> X




Termination of R could not be shown.
Duration:
0:00 minutes