YES Termination w.r.t. Q proof of /home/cern_httpd/provide/research/cycsrs/tpdb/TPDB-d9b80194f163/SRS_Standard/Zantema_04/z117.srs

(0) Obligation:

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

d(a(x)) → b(d(x))
b(x) → a(a(a(x)))
c(d(c(x))) → a(d(x))
b(d(d(x))) → c(c(d(d(c(x)))))

Q is empty.

(1) QTRS Reverse (EQUIVALENT transformation)

We applied the QTRS Reverse Processor [REVERSE].

(2) Obligation:

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

a(d(x)) → d(b(x))
b(x) → a(a(a(x)))
c(d(c(x))) → d(a(x))
d(d(b(x))) → c(d(d(c(c(x)))))

Q is empty.

(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:

A(d(x)) → D(b(x))
A(d(x)) → B(x)
B(x) → A(a(a(x)))
B(x) → A(a(x))
B(x) → A(x)
C(d(c(x))) → D(a(x))
C(d(c(x))) → A(x)
D(d(b(x))) → C(d(d(c(c(x)))))
D(d(b(x))) → D(d(c(c(x))))
D(d(b(x))) → D(c(c(x)))
D(d(b(x))) → C(c(x))
D(d(b(x))) → C(x)

The TRS R consists of the following rules:

a(d(x)) → d(b(x))
b(x) → a(a(a(x)))
c(d(c(x))) → d(a(x))
d(d(b(x))) → c(d(d(c(c(x)))))

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

(5) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04,JAR06].


The following pairs can be oriented strictly and are deleted.


A(d(x)) → B(x)
C(d(c(x))) → A(x)
D(d(b(x))) → D(c(c(x)))
D(d(b(x))) → C(c(x))
D(d(b(x))) → C(x)
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial interpretation [POLO]:

POL(A(x1)) = x1   
POL(B(x1)) = x1   
POL(C(x1)) = x1   
POL(D(x1)) = 1 + x1   
POL(a(x1)) = x1   
POL(b(x1)) = x1   
POL(c(x1)) = x1   
POL(d(x1)) = 1 + x1   

The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:

b(x) → a(a(a(x)))
a(d(x)) → d(b(x))
d(d(b(x))) → c(d(d(c(c(x)))))
c(d(c(x))) → d(a(x))

(6) Obligation:

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

A(d(x)) → D(b(x))
B(x) → A(a(a(x)))
B(x) → A(a(x))
B(x) → A(x)
C(d(c(x))) → D(a(x))
D(d(b(x))) → C(d(d(c(c(x)))))
D(d(b(x))) → D(d(c(c(x))))

The TRS R consists of the following rules:

a(d(x)) → d(b(x))
b(x) → a(a(a(x)))
c(d(c(x))) → d(a(x))
d(d(b(x))) → c(d(d(c(c(x)))))

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

(7) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 4 less nodes.

(8) Obligation:

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

D(d(b(x))) → C(d(d(c(c(x)))))
C(d(c(x))) → D(a(x))
D(d(b(x))) → D(d(c(c(x))))

The TRS R consists of the following rules:

a(d(x)) → d(b(x))
b(x) → a(a(a(x)))
c(d(c(x))) → d(a(x))
d(d(b(x))) → c(d(d(c(c(x)))))

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

(9) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04,JAR06].


The following pairs can be oriented strictly and are deleted.


D(d(b(x))) → D(d(c(c(x))))
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial Order [NEGPOLO,POLO] with Interpretation:
POL( C(x1) ) = 1

POL( D(x1) ) = max{0, 2x1 - 1}

POL( d(x1) ) = max{0, x1 - 1}

POL( b(x1) ) = 2

POL( c(x1) ) = max{0, -2}

POL( a(x1) ) = 1


The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:

d(d(b(x))) → c(d(d(c(c(x)))))
c(d(c(x))) → d(a(x))
a(d(x)) → d(b(x))
b(x) → a(a(a(x)))

(10) Obligation:

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

D(d(b(x))) → C(d(d(c(c(x)))))
C(d(c(x))) → D(a(x))

The TRS R consists of the following rules:

a(d(x)) → d(b(x))
b(x) → a(a(a(x)))
c(d(c(x))) → d(a(x))
d(d(b(x))) → c(d(d(c(c(x)))))

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

(11) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04,JAR06].


The following pairs can be oriented strictly and are deleted.


C(d(c(x))) → D(a(x))
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:

POL(D(x1)) = 0A +
[-I,-I,0A]
·x1

POL(d(x1)) =
/0A\
|0A|
\1A/
+
/-I0A0A\
|1A-I0A|
\0A0A1A/
·x1

POL(b(x1)) =
/1A\
|1A|
\0A/
+
/0A0A1A\
|0A0A1A|
\-I-I0A/
·x1

POL(C(x1)) = 0A +
[-I,0A,-I]
·x1

POL(c(x1)) =
/0A\
|0A|
\0A/
+
/0A0A0A\
|-I-I0A|
\-I-I0A/
·x1

POL(a(x1)) =
/0A\
|0A|
\0A/
+
/-I-I0A\
|0A0A1A|
\-I-I0A/
·x1

The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:

d(d(b(x))) → c(d(d(c(c(x)))))
c(d(c(x))) → d(a(x))
a(d(x)) → d(b(x))
b(x) → a(a(a(x)))

(12) Obligation:

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

D(d(b(x))) → C(d(d(c(c(x)))))

The TRS R consists of the following rules:

a(d(x)) → d(b(x))
b(x) → a(a(a(x)))
c(d(c(x))) → d(a(x))
d(d(b(x))) → c(d(d(c(c(x)))))

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

(13) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node.

(14) TRUE