Term Rewriting System R:
[x]
f(a, f(f(a, x), a)) -> f(f(a, f(a, x)), a)

Termination of R to be shown.

`   R`
`     ↳Dependency Pair Analysis`

R contains the following Dependency Pairs:

F(a, f(f(a, x), a)) -> F(f(a, f(a, x)), a)
F(a, f(f(a, x), a)) -> F(a, f(a, x))

Furthermore, R contains one SCC.

`   R`
`     ↳DPs`
`       →DP Problem 1`
`         ↳Narrowing Transformation`

Dependency Pair:

F(a, f(f(a, x), a)) -> F(a, f(a, x))

Rule:

f(a, f(f(a, x), a)) -> f(f(a, f(a, x)), a)

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

F(a, f(f(a, x), a)) -> F(a, f(a, x))
one new Dependency Pair is created:

F(a, f(f(a, f(f(a, x''), a)), a)) -> F(a, f(f(a, f(a, x'')), a))

The transformation is resulting in one new DP problem:

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

Dependency Pair:

F(a, f(f(a, f(f(a, x''), a)), a)) -> F(a, f(f(a, f(a, x'')), a))

Rule:

f(a, f(f(a, x), a)) -> f(f(a, f(a, x)), a)

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

F(a, f(f(a, f(f(a, x''), a)), a)) -> F(a, f(f(a, f(a, x'')), a))
one new Dependency Pair is created:

F(a, f(f(a, f(f(a, f(f(a, x'), a)), a)), a)) -> F(a, f(f(a, f(f(a, f(a, x')), a)), a))

The transformation is resulting in one new DP problem:

`   R`
`     ↳DPs`
`       →DP Problem 1`
`         ↳Nar`
`           →DP Problem 2`
`             ↳Nar`
`             ...`
`               →DP Problem 3`
`                 ↳Polynomial Ordering`

Dependency Pair:

F(a, f(f(a, f(f(a, f(f(a, x'), a)), a)), a)) -> F(a, f(f(a, f(f(a, f(a, x')), a)), a))

Rule:

f(a, f(f(a, x), a)) -> f(f(a, f(a, x)), a)

The following dependency pair can be strictly oriented:

F(a, f(f(a, f(f(a, f(f(a, x'), a)), a)), a)) -> F(a, f(f(a, f(f(a, f(a, x')), a)), a))

Additionally, the following usable rule w.r.t. to the implicit AFS can be oriented:

f(a, f(f(a, x), a)) -> f(f(a, f(a, x)), a)

Used ordering: Polynomial ordering with Polynomial interpretation:
 POL(a) =  0 POL(f(x1, x2)) =  1 + x1 + x2 POL(F(x1, x2)) =  1 + x2

resulting in one new DP problem.

`   R`
`     ↳DPs`
`       →DP Problem 1`
`         ↳Nar`
`           →DP Problem 2`
`             ↳Nar`
`             ...`
`               →DP Problem 4`
`                 ↳Dependency Graph`

Dependency Pair:

Rule:

f(a, f(f(a, x), a)) -> f(f(a, f(a, x)), a)

Using the Dependency Graph resulted in no new DP problems.

Termination of R successfully shown.
Duration:
0:00 minutes