YES Termination w.r.t. Q proof of /home/cern_httpd/provide/research/cycsrs/tpdb/TPDB-d9b80194f163/SRS_Standard/Zantema_04/z101-shift.srs

(0) Obligation:

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

B(x) → W(M(M(M(M(V(x))))))
M(x) → x
M(V(a(x))) → V(Xa(x))
M(V(b(x))) → V(Xb(x))
Xa(a(x)) → a(Xa(x))
Xa(b(x)) → b(Xa(x))
Xb(a(x)) → a(Xb(x))
Xb(b(x)) → b(Xb(x))
Xa(E(x)) → a(E(x))
Xb(E(x)) → b(E(x))
W(V(x)) → R(L(x))
L(a(x)) → Ya(L(x))
L(b(x)) → Yb(L(x))
L(a(a(x))) → D(b(b(b(x))))
L(b(b(b(b(b(x)))))) → D(a(a(a(x))))
Ya(D(x)) → D(a(x))
Yb(D(x)) → D(b(x))
R(D(x)) → B(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:

B(x) → V(M(M(M(M(W(x))))))
M(x) → x
a(V(M(x))) → Xa(V(x))
b(V(M(x))) → Xb(V(x))
a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
E(Xa(x)) → E(a(x))
E(Xb(x)) → E(b(x))
V(W(x)) → L(R(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
a(a(L(x))) → b(b(b(D(x))))
b(b(b(b(b(L(x)))))) → a(a(a(D(x))))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))
D(R(x)) → B(x)

Q is empty.

(3) QTRSRRRProof (EQUIVALENT transformation)

Used ordering:
Polynomial interpretation [POLO]:

POL(B(x1)) = 10 + x1   
POL(D(x1)) = 11 + x1   
POL(E(x1)) = x1   
POL(L(x1)) = x1   
POL(M(x1)) = 2 + x1   
POL(R(x1)) = x1   
POL(V(x1)) = 1 + x1   
POL(W(x1)) = x1   
POL(Xa(x1)) = 97 + x1   
POL(Xb(x1)) = 61 + x1   
POL(Ya(x1)) = 96 + x1   
POL(Yb(x1)) = 60 + x1   
POL(a(x1)) = 96 + x1   
POL(b(x1)) = 60 + x1   
With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly:

B(x) → V(M(M(M(M(W(x))))))
M(x) → x
a(V(M(x))) → Xa(V(x))
b(V(M(x))) → Xb(V(x))
E(Xa(x)) → E(a(x))
E(Xb(x)) → E(b(x))
V(W(x)) → L(R(x))
a(a(L(x))) → b(b(b(D(x))))
b(b(b(b(b(L(x)))))) → a(a(a(D(x))))
D(R(x)) → B(x)


(4) Obligation:

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

a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))

Q is empty.

(5) Overlay + Local Confluence (EQUIVALENT transformation)

The TRS is overlay and locally confluent. By [NOC] we can switch to innermost.

(6) Obligation:

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

a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))

The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

(7) DependencyPairsProof (EQUIVALENT transformation)

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

(8) Obligation:

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

A(Xa(x)) → A(x)
B(Xa(x)) → B(x)
A(Xb(x)) → A(x)
B(Xb(x)) → B(x)
D1(Ya(x)) → A(D(x))
D1(Ya(x)) → D1(x)
D1(Yb(x)) → B(D(x))
D1(Yb(x)) → D1(x)

The TRS R consists of the following rules:

a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))

The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(9) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 3 SCCs with 2 less nodes.

(10) Complex Obligation (AND)

(11) Obligation:

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

B(Xb(x)) → B(x)
B(Xa(x)) → B(x)

The TRS R consists of the following rules:

a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))

The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(12) 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.

(13) Obligation:

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

B(Xb(x)) → B(x)
B(Xa(x)) → B(x)

R is empty.
The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(14) 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].

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

(15) Obligation:

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

B(Xb(x)) → B(x)
B(Xa(x)) → B(x)

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

(16) QDPSizeChangeProof (EQUIVALENT transformation)

By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:

  • B(Xb(x)) → B(x)
    The graph contains the following edges 1 > 1

  • B(Xa(x)) → B(x)
    The graph contains the following edges 1 > 1

(17) YES

(18) Obligation:

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

A(Xb(x)) → A(x)
A(Xa(x)) → A(x)

The TRS R consists of the following rules:

a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))

The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(19) 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.

(20) Obligation:

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

A(Xb(x)) → A(x)
A(Xa(x)) → A(x)

R is empty.
The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(21) 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].

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

(22) Obligation:

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

A(Xb(x)) → A(x)
A(Xa(x)) → A(x)

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

(23) QDPSizeChangeProof (EQUIVALENT transformation)

By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:

  • A(Xb(x)) → A(x)
    The graph contains the following edges 1 > 1

  • A(Xa(x)) → A(x)
    The graph contains the following edges 1 > 1

(24) YES

(25) Obligation:

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

D1(Yb(x)) → D1(x)
D1(Ya(x)) → D1(x)

The TRS R consists of the following rules:

a(Xa(x)) → Xa(a(x))
b(Xa(x)) → Xa(b(x))
a(Xb(x)) → Xb(a(x))
b(Xb(x)) → Xb(b(x))
a(L(x)) → L(Ya(x))
b(L(x)) → L(Yb(x))
D(Ya(x)) → a(D(x))
D(Yb(x)) → b(D(x))

The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(26) 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.

(27) Obligation:

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

D1(Yb(x)) → D1(x)
D1(Ya(x)) → D1(x)

R is empty.
The set Q consists of the following terms:

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

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

(28) 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].

a(Xa(x0))
b(Xa(x0))
a(Xb(x0))
b(Xb(x0))
a(L(x0))
b(L(x0))
D(Ya(x0))
D(Yb(x0))

(29) Obligation:

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

D1(Yb(x)) → D1(x)
D1(Ya(x)) → D1(x)

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

(30) QDPSizeChangeProof (EQUIVALENT transformation)

By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:

  • D1(Yb(x)) → D1(x)
    The graph contains the following edges 1 > 1

  • D1(Ya(x)) → D1(x)
    The graph contains the following edges 1 > 1

(31) YES