(0) Obligation:

Q restricted rewrite system:
The TRS R consists of the following rules:

f(s(x), y) → f(x, s(x))
f(x, s(y)) → f(y, x)

Q is empty.

(1) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.

(2) Obligation:

Q DP problem:
The TRS P consists of the following rules:

F(s(x), y) → F(x, s(x))
F(x, s(y)) → F(y, x)

The TRS R consists of the following rules:

f(s(x), y) → f(x, s(x))
f(x, s(y)) → f(y, x)

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

(3) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04].


The following pairs can be oriented strictly and are deleted.


F(s(x), y) → F(x, s(x))
F(x, s(y)) → F(y, x)
The remaining pairs can at least be oriented weakly.
Used ordering: SCNP Order with the following components:
Level mapping:
Top level AFS:
F(x0, x1, x2)  =  F(x1, x2)

Tags:
F has argument tags [1,2,1] and root tag 0

Comparison: MAX
Underlying order for the size change arcs and the rules of R:
Combined order from the following AFS and order.
F(x1, x2)  =  F(x1)
s(x1)  =  s(x1)

Lexicographic path order with status [LPO].
Quasi-Precedence:
F1 > s1

Status:
F1: [1]
s1: [1]


The following usable rules [FROCOS05] were oriented: none

(4) Obligation:

Q DP problem:
P is empty.
The TRS R consists of the following rules:

f(s(x), y) → f(x, s(x))
f(x, s(y)) → f(y, x)

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

(5) PisEmptyProof (EQUIVALENT transformation)

The TRS P is empty. Hence, there is no (P,Q,R) chain.

(6) TRUE