Term Rewriting System R:
[X, Y, X1, X2]
afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0

Innermost Termination of R to be shown.



   R
Dependency Pair Analysis



R contains the following Dependency Pairs:

AFROM(X) -> MARK(X)
ALENGTH(cons(X, Y)) -> ALENGTH1(Y)
ALENGTH1(X) -> ALENGTH(X)
MARK(from(X)) -> AFROM(mark(X))
MARK(from(X)) -> MARK(X)
MARK(length(X)) -> ALENGTH(X)
MARK(length1(X)) -> ALENGTH1(X)
MARK(cons(X1, X2)) -> MARK(X1)
MARK(s(X)) -> MARK(X)

Furthermore, R contains two SCCs.


   R
DPs
       →DP Problem 1
Argument Filtering and Ordering
       →DP Problem 2
FwdInst


Dependency Pairs:

ALENGTH1(X) -> ALENGTH(X)
ALENGTH(cons(X, Y)) -> ALENGTH1(Y)


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




The following dependency pair can be strictly oriented:

ALENGTH(cons(X, Y)) -> ALENGTH1(Y)


There are no usable rules for innermost w.r.t. to the AFS that need to be oriented.
Used ordering: Homeomorphic Embedding Order with EMB
resulting in one new DP problem.
Used Argument Filtering System:
ALENGTH1(x1) -> x1
ALENGTH(x1) -> x1
cons(x1, x2) -> cons(x1, x2)


   R
DPs
       →DP Problem 1
AFS
           →DP Problem 3
Dependency Graph
       →DP Problem 2
FwdInst


Dependency Pair:

ALENGTH1(X) -> ALENGTH(X)


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




Using the Dependency Graph resulted in no new DP problems.


   R
DPs
       →DP Problem 1
AFS
       →DP Problem 2
Forward Instantiation Transformation


Dependency Pairs:

MARK(s(X)) -> MARK(X)
MARK(cons(X1, X2)) -> MARK(X1)
MARK(from(X)) -> MARK(X)
MARK(from(X)) -> AFROM(mark(X))
AFROM(X) -> MARK(X)


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




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

AFROM(X) -> MARK(X)
three new Dependency Pairs are created:

AFROM(from(X'')) -> MARK(from(X''))
AFROM(cons(X1'', X2'')) -> MARK(cons(X1'', X2''))
AFROM(s(X'')) -> MARK(s(X''))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
AFS
       →DP Problem 2
FwdInst
           →DP Problem 4
Narrowing Transformation


Dependency Pairs:

AFROM(s(X'')) -> MARK(s(X''))
AFROM(cons(X1'', X2'')) -> MARK(cons(X1'', X2''))
MARK(cons(X1, X2)) -> MARK(X1)
MARK(from(X)) -> MARK(X)
AFROM(from(X'')) -> MARK(from(X''))
MARK(from(X)) -> AFROM(mark(X))
MARK(s(X)) -> MARK(X)


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




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

MARK(from(X)) -> AFROM(mark(X))
seven new Dependency Pairs are created:

MARK(from(from(X''))) -> AFROM(afrom(mark(X'')))
MARK(from(length(X''))) -> AFROM(alength(X''))
MARK(from(length1(X''))) -> AFROM(alength1(X''))
MARK(from(cons(X1', X2'))) -> AFROM(cons(mark(X1'), X2'))
MARK(from(s(X''))) -> AFROM(s(mark(X'')))
MARK(from(nil)) -> AFROM(nil)
MARK(from(0)) -> AFROM(0)

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
AFS
       →DP Problem 2
FwdInst
           →DP Problem 4
Nar
             ...
               →DP Problem 5
Forward Instantiation Transformation


Dependency Pairs:

MARK(from(s(X''))) -> AFROM(s(mark(X'')))
MARK(from(cons(X1', X2'))) -> AFROM(cons(mark(X1'), X2'))
MARK(from(length1(X''))) -> AFROM(alength1(X''))
AFROM(cons(X1'', X2'')) -> MARK(cons(X1'', X2''))
MARK(from(length(X''))) -> AFROM(alength(X''))
AFROM(from(X'')) -> MARK(from(X''))
MARK(from(from(X''))) -> AFROM(afrom(mark(X'')))
MARK(cons(X1, X2)) -> MARK(X1)
MARK(from(X)) -> MARK(X)
MARK(s(X)) -> MARK(X)
AFROM(s(X'')) -> MARK(s(X''))


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




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

MARK(from(X)) -> MARK(X)
eight new Dependency Pairs are created:

MARK(from(from(X''))) -> MARK(from(X''))
MARK(from(cons(X1'', X2''))) -> MARK(cons(X1'', X2''))
MARK(from(s(X''))) -> MARK(s(X''))
MARK(from(from(from(X'''')))) -> MARK(from(from(X'''')))
MARK(from(from(length(X'''')))) -> MARK(from(length(X'''')))
MARK(from(from(length1(X'''')))) -> MARK(from(length1(X'''')))
MARK(from(from(cons(X1''', X2''')))) -> MARK(from(cons(X1''', X2''')))
MARK(from(from(s(X'''')))) -> MARK(from(s(X'''')))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
AFS
       →DP Problem 2
FwdInst
           →DP Problem 4
Nar
             ...
               →DP Problem 6
Forward Instantiation Transformation


Dependency Pairs:

MARK(from(from(s(X'''')))) -> MARK(from(s(X'''')))
MARK(from(from(cons(X1''', X2''')))) -> MARK(from(cons(X1''', X2''')))
MARK(from(from(length1(X'''')))) -> MARK(from(length1(X'''')))
MARK(from(from(length(X'''')))) -> MARK(from(length(X'''')))
MARK(from(from(from(X'''')))) -> MARK(from(from(X'''')))
MARK(from(s(X''))) -> MARK(s(X''))
MARK(from(cons(X1'', X2''))) -> MARK(cons(X1'', X2''))
MARK(from(from(X''))) -> MARK(from(X''))
MARK(from(cons(X1', X2'))) -> AFROM(cons(mark(X1'), X2'))
MARK(from(length1(X''))) -> AFROM(alength1(X''))
AFROM(cons(X1'', X2'')) -> MARK(cons(X1'', X2''))
MARK(from(length(X''))) -> AFROM(alength(X''))
AFROM(from(X'')) -> MARK(from(X''))
MARK(from(from(X''))) -> AFROM(afrom(mark(X'')))
MARK(cons(X1, X2)) -> MARK(X1)
MARK(s(X)) -> MARK(X)
AFROM(s(X'')) -> MARK(s(X''))
MARK(from(s(X''))) -> AFROM(s(mark(X'')))


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




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

MARK(cons(X1, X2)) -> MARK(X1)
13 new Dependency Pairs are created:

MARK(cons(cons(X1'', X2''), X2)) -> MARK(cons(X1'', X2''))
MARK(cons(s(X''), X2)) -> MARK(s(X''))
MARK(cons(from(from(X'''')), X2)) -> MARK(from(from(X'''')))
MARK(cons(from(length(X'''')), X2)) -> MARK(from(length(X'''')))
MARK(cons(from(length1(X'''')), X2)) -> MARK(from(length1(X'''')))
MARK(cons(from(cons(X1''', X2''')), X2)) -> MARK(from(cons(X1''', X2''')))
MARK(cons(from(s(X'''')), X2)) -> MARK(from(s(X'''')))
MARK(cons(from(cons(X1'''', X2'''')), X2)) -> MARK(from(cons(X1'''', X2'''')))
MARK(cons(from(from(from(X''''''))), X2)) -> MARK(from(from(from(X''''''))))
MARK(cons(from(from(length(X''''''))), X2)) -> MARK(from(from(length(X''''''))))
MARK(cons(from(from(length1(X''''''))), X2)) -> MARK(from(from(length1(X''''''))))
MARK(cons(from(from(cons(X1''''', X2'''''))), X2)) -> MARK(from(from(cons(X1''''', X2'''''))))
MARK(cons(from(from(s(X''''''))), X2)) -> MARK(from(from(s(X''''''))))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
AFS
       →DP Problem 2
FwdInst
           →DP Problem 4
Nar
             ...
               →DP Problem 7
Forward Instantiation Transformation


Dependency Pairs:

MARK(cons(from(from(s(X''''''))), X2)) -> MARK(from(from(s(X''''''))))
MARK(cons(from(from(cons(X1''''', X2'''''))), X2)) -> MARK(from(from(cons(X1''''', X2'''''))))
MARK(cons(from(from(length1(X''''''))), X2)) -> MARK(from(from(length1(X''''''))))
MARK(cons(from(from(length(X''''''))), X2)) -> MARK(from(from(length(X''''''))))
MARK(from(from(cons(X1''', X2''')))) -> MARK(from(cons(X1''', X2''')))
MARK(from(from(length1(X'''')))) -> MARK(from(length1(X'''')))
MARK(from(from(length(X'''')))) -> MARK(from(length(X'''')))
MARK(from(from(from(X'''')))) -> MARK(from(from(X'''')))
MARK(cons(from(from(from(X''''''))), X2)) -> MARK(from(from(from(X''''''))))
MARK(cons(from(cons(X1'''', X2'''')), X2)) -> MARK(from(cons(X1'''', X2'''')))
MARK(from(s(X''))) -> MARK(s(X''))
MARK(cons(from(s(X'''')), X2)) -> MARK(from(s(X'''')))
MARK(cons(from(cons(X1''', X2''')), X2)) -> MARK(from(cons(X1''', X2''')))
MARK(cons(from(length1(X'''')), X2)) -> MARK(from(length1(X'''')))
MARK(cons(from(length(X'''')), X2)) -> MARK(from(length(X'''')))
MARK(from(cons(X1'', X2''))) -> MARK(cons(X1'', X2''))
MARK(from(cons(X1', X2'))) -> AFROM(cons(mark(X1'), X2'))
MARK(from(length1(X''))) -> AFROM(alength1(X''))
MARK(from(from(X''))) -> MARK(from(X''))
MARK(cons(from(from(X'''')), X2)) -> MARK(from(from(X'''')))
MARK(cons(s(X''), X2)) -> MARK(s(X''))
MARK(cons(cons(X1'', X2''), X2)) -> MARK(cons(X1'', X2''))
AFROM(cons(X1'', X2'')) -> MARK(cons(X1'', X2''))
MARK(from(length(X''))) -> AFROM(alength(X''))
AFROM(from(X'')) -> MARK(from(X''))
MARK(from(from(X''))) -> AFROM(afrom(mark(X'')))
MARK(s(X)) -> MARK(X)
AFROM(s(X'')) -> MARK(s(X''))
MARK(from(s(X''))) -> AFROM(s(mark(X'')))
MARK(from(from(s(X'''')))) -> MARK(from(s(X'''')))


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost




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

MARK(s(X)) -> MARK(X)
25 new Dependency Pairs are created:

MARK(s(s(X''))) -> MARK(s(X''))
MARK(s(from(from(X'''')))) -> MARK(from(from(X'''')))
MARK(s(from(length(X'''')))) -> MARK(from(length(X'''')))
MARK(s(from(length1(X'''')))) -> MARK(from(length1(X'''')))
MARK(s(from(cons(X1''', X2''')))) -> MARK(from(cons(X1''', X2''')))
MARK(s(from(s(X'''')))) -> MARK(from(s(X'''')))
MARK(s(from(cons(X1'''', X2'''')))) -> MARK(from(cons(X1'''', X2'''')))
MARK(s(from(from(from(X''''''))))) -> MARK(from(from(from(X''''''))))
MARK(s(from(from(length(X''''''))))) -> MARK(from(from(length(X''''''))))
MARK(s(from(from(length1(X''''''))))) -> MARK(from(from(length1(X''''''))))
MARK(s(from(from(cons(X1''''', X2'''''))))) -> MARK(from(from(cons(X1''''', X2'''''))))
MARK(s(from(from(s(X''''''))))) -> MARK(from(from(s(X''''''))))
MARK(s(cons(cons(X1'''', X2''''), X2''))) -> MARK(cons(cons(X1'''', X2''''), X2''))
MARK(s(cons(s(X''''), X2''))) -> MARK(cons(s(X''''), X2''))
MARK(s(cons(from(from(X'''''')), X2''))) -> MARK(cons(from(from(X'''''')), X2''))
MARK(s(cons(from(length(X'''''')), X2''))) -> MARK(cons(from(length(X'''''')), X2''))
MARK(s(cons(from(length1(X'''''')), X2''))) -> MARK(cons(from(length1(X'''''')), X2''))
MARK(s(cons(from(cons(X1''''', X2''''')), X2''))) -> MARK(cons(from(cons(X1''''', X2''''')), X2''))
MARK(s(cons(from(s(X'''''')), X2''))) -> MARK(cons(from(s(X'''''')), X2''))
MARK(s(cons(from(cons(X1'''''', X2'''''')), X2''))) -> MARK(cons(from(cons(X1'''''', X2'''''')), X2''))
MARK(s(cons(from(from(from(X''''''''))), X2''))) -> MARK(cons(from(from(from(X''''''''))), X2''))
MARK(s(cons(from(from(length(X''''''''))), X2''))) -> MARK(cons(from(from(length(X''''''''))), X2''))
MARK(s(cons(from(from(length1(X''''''''))), X2''))) -> MARK(cons(from(from(length1(X''''''''))), X2''))
MARK(s(cons(from(from(cons(X1''''''', X2'''''''))), X2''))) -> MARK(cons(from(from(cons(X1''''''', X2'''''''))), X2''))
MARK(s(cons(from(from(s(X''''''''))), X2''))) -> MARK(cons(from(from(s(X''''''''))), X2''))

The transformation is resulting in one new DP problem:



   R
DPs
       →DP Problem 1
AFS
       →DP Problem 2
FwdInst
           →DP Problem 4
Nar
             ...
               →DP Problem 8
Remaining Obligation(s)




The following remains to be proven:
Dependency Pairs:

MARK(s(cons(from(from(s(X''''''''))), X2''))) -> MARK(cons(from(from(s(X''''''''))), X2''))
MARK(s(cons(from(from(cons(X1''''''', X2'''''''))), X2''))) -> MARK(cons(from(from(cons(X1''''''', X2'''''''))), X2''))
MARK(s(cons(from(from(length1(X''''''''))), X2''))) -> MARK(cons(from(from(length1(X''''''''))), X2''))
MARK(s(cons(from(from(length(X''''''''))), X2''))) -> MARK(cons(from(from(length(X''''''''))), X2''))
MARK(s(cons(from(from(from(X''''''''))), X2''))) -> MARK(cons(from(from(from(X''''''''))), X2''))
MARK(s(cons(from(cons(X1'''''', X2'''''')), X2''))) -> MARK(cons(from(cons(X1'''''', X2'''''')), X2''))
MARK(cons(from(s(X'''')), X2)) -> MARK(from(s(X'''')))
MARK(s(cons(from(s(X'''''')), X2''))) -> MARK(cons(from(s(X'''''')), X2''))
MARK(cons(from(cons(X1'''', X2'''')), X2)) -> MARK(from(cons(X1'''', X2'''')))
MARK(cons(from(cons(X1''', X2''')), X2)) -> MARK(from(cons(X1''', X2''')))
MARK(s(cons(from(cons(X1''''', X2''''')), X2''))) -> MARK(cons(from(cons(X1''''', X2''''')), X2''))
MARK(cons(from(length1(X'''')), X2)) -> MARK(from(length1(X'''')))
MARK(s(cons(from(length1(X'''''')), X2''))) -> MARK(cons(from(length1(X'''''')), X2''))
MARK(cons(from(length(X'''')), X2)) -> MARK(from(length(X'''')))
MARK(s(cons(from(length(X'''''')), X2''))) -> MARK(cons(from(length(X'''''')), X2''))
MARK(cons(from(from(cons(X1''''', X2'''''))), X2)) -> MARK(from(from(cons(X1''''', X2'''''))))
MARK(cons(from(from(length1(X''''''))), X2)) -> MARK(from(from(length1(X''''''))))
MARK(cons(from(from(length(X''''''))), X2)) -> MARK(from(from(length(X''''''))))
MARK(cons(from(from(from(X''''''))), X2)) -> MARK(from(from(from(X''''''))))
MARK(s(cons(from(from(X'''''')), X2''))) -> MARK(cons(from(from(X'''''')), X2''))
MARK(s(cons(s(X''''), X2''))) -> MARK(cons(s(X''''), X2''))
MARK(s(cons(cons(X1'''', X2''''), X2''))) -> MARK(cons(cons(X1'''', X2''''), X2''))
MARK(s(from(from(s(X''''''))))) -> MARK(from(from(s(X''''''))))
MARK(s(from(from(cons(X1''''', X2'''''))))) -> MARK(from(from(cons(X1''''', X2'''''))))
MARK(s(from(from(length1(X''''''))))) -> MARK(from(from(length1(X''''''))))
MARK(s(from(from(length(X''''''))))) -> MARK(from(from(length(X''''''))))
MARK(s(from(from(from(X''''''))))) -> MARK(from(from(from(X''''''))))
MARK(s(from(cons(X1'''', X2'''')))) -> MARK(from(cons(X1'''', X2'''')))
MARK(s(from(s(X'''')))) -> MARK(from(s(X'''')))
MARK(from(s(X''))) -> MARK(s(X''))
MARK(from(s(X''))) -> AFROM(s(mark(X'')))
MARK(from(from(s(X'''')))) -> MARK(from(s(X'''')))
MARK(from(from(cons(X1''', X2''')))) -> MARK(from(cons(X1''', X2''')))
MARK(from(from(length1(X'''')))) -> MARK(from(length1(X'''')))
MARK(from(from(length(X'''')))) -> MARK(from(length(X'''')))
MARK(from(from(from(X'''')))) -> MARK(from(from(X'''')))
MARK(cons(from(from(X'''')), X2)) -> MARK(from(from(X'''')))
MARK(from(cons(X1'', X2''))) -> MARK(cons(X1'', X2''))
MARK(from(cons(X1', X2'))) -> AFROM(cons(mark(X1'), X2'))
MARK(s(from(cons(X1''', X2''')))) -> MARK(from(cons(X1''', X2''')))
MARK(s(from(length1(X'''')))) -> MARK(from(length1(X'''')))
MARK(s(from(length(X'''')))) -> MARK(from(length(X'''')))
AFROM(s(X'')) -> MARK(s(X''))
MARK(from(length1(X''))) -> AFROM(alength1(X''))
MARK(from(from(X''))) -> MARK(from(X''))
MARK(s(from(from(X'''')))) -> MARK(from(from(X'''')))
MARK(s(s(X''))) -> MARK(s(X''))
MARK(cons(s(X''), X2)) -> MARK(s(X''))
MARK(cons(cons(X1'', X2''), X2)) -> MARK(cons(X1'', X2''))
AFROM(cons(X1'', X2'')) -> MARK(cons(X1'', X2''))
MARK(from(length(X''))) -> AFROM(alength(X''))
AFROM(from(X'')) -> MARK(from(X''))
MARK(from(from(X''))) -> AFROM(afrom(mark(X'')))
MARK(cons(from(from(s(X''''''))), X2)) -> MARK(from(from(s(X''''''))))


Rules:


afrom(X) -> cons(mark(X), from(s(X)))
afrom(X) -> from(X)
alength(nil) -> 0
alength(cons(X, Y)) -> s(alength1(Y))
alength(X) -> length(X)
alength1(X) -> alength(X)
alength1(X) -> length1(X)
mark(from(X)) -> afrom(mark(X))
mark(length(X)) -> alength(X)
mark(length1(X)) -> alength1(X)
mark(cons(X1, X2)) -> cons(mark(X1), X2)
mark(s(X)) -> s(mark(X))
mark(nil) -> nil
mark(0) -> 0


Strategy:

innermost



Innermost Termination of R could not be shown.
Duration:
0:24 minutes