(0) Obligation:

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

f(a, y) → f(y, g(y))
g(a) → b
g(b) → b

Q is empty.

(1) AAECC Innermost (EQUIVALENT transformation)

We have applied [NOC,AAECCNOC] to switch to innermost. The TRS R 1 is

g(a) → b
g(b) → b

The TRS R 2 is

f(a, y) → f(y, g(y))

The signature Sigma is {f}

(2) Obligation:

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

f(a, y) → f(y, g(y))
g(a) → b
g(b) → b

The set Q consists of the following terms:

f(a, x0)
g(a)
g(b)

(3) DependencyPairsProof (EQUIVALENT transformation)

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

(4) Obligation:

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

F(a, y) → F(y, g(y))
F(a, y) → G(y)

The TRS R consists of the following rules:

f(a, y) → f(y, g(y))
g(a) → b
g(b) → b

The set Q consists of the following terms:

f(a, x0)
g(a)
g(b)

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

(5) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node.

(6) Obligation:

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

F(a, y) → F(y, g(y))

The TRS R consists of the following rules:

f(a, y) → f(y, g(y))
g(a) → b
g(b) → b

The set Q consists of the following terms:

f(a, x0)
g(a)
g(b)

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

(7) UsableRulesProof (EQUIVALENT transformation)

As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [LPAR04] we can delete all non-usable rules [FROCOS05] from R.

(8) Obligation:

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

F(a, y) → F(y, g(y))

The TRS R consists of the following rules:

g(a) → b
g(b) → b

The set Q consists of the following terms:

f(a, x0)
g(a)
g(b)

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

(9) QReductionProof (EQUIVALENT transformation)

We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.[THIEMANN].

f(a, x0)

(10) Obligation:

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

F(a, y) → F(y, g(y))

The TRS R consists of the following rules:

g(a) → b
g(b) → b

The set Q consists of the following terms:

g(a)
g(b)

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

(11) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04].


The following pairs can be oriented strictly and are deleted.


F(a, y) → F(y, g(y))
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO]:

POL(F(x1, x2)) =
/0\
\1/
+
/01\
\01/
·x1 +
/01\
\01/
·x2

POL(a) =
/0\
\1/

POL(g(x1)) =
/1\
\0/
+
/11\
\00/
·x1

POL(b) =
/1\
\0/

The following usable rules [FROCOS05] were oriented:

g(b) → b
g(a) → b

(12) Obligation:

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

g(a) → b
g(b) → b

The set Q consists of the following terms:

g(a)
g(b)

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

(13) PisEmptyProof (EQUIVALENT transformation)

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

(14) TRUE