(0) Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
c(b(x)) → b(a(d(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
(1) QTRSRRRProof (EQUIVALENT transformation)
Used ordering:
Polynomial interpretation [POLO]:
POL(a(x1)) = x1
POL(b(x1)) = x1
POL(c(x1)) = 1 + x1
POL(d(x1)) = x1
With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly:
c(b(x)) → b(a(d(x)))
(2) Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(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(a(x)) → A(b(a(b(a(x)))))
A(a(x)) → B(a(b(a(x))))
A(a(x)) → A(b(a(x)))
A(a(x)) → B(a(x))
C(a(x)) → A(b(a(a(c(x)))))
C(a(x)) → B(a(a(c(x))))
C(a(x)) → A(a(c(x)))
C(a(x)) → A(c(x))
C(a(x)) → C(x)
B(b(b(x))) → A(b(x))
C(b(x)) → A(a(c(x)))
C(b(x)) → A(c(x))
C(b(x)) → C(x)
D(d(x)) → D(b(d(b(d(x)))))
D(d(x)) → B(d(b(d(x))))
D(d(x)) → D(b(d(x)))
D(d(x)) → B(d(x))
C(c(x)) → C(d(c(x)))
C(c(x)) → D(c(x))
A(a(a(x))) → A(b(b(x)))
A(a(a(x))) → B(b(x))
A(a(a(x))) → B(x)
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(5) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 3 SCCs with 11 less nodes.
(6) Complex Obligation (AND)
(7) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(x)) → A(b(a(x)))
A(a(x)) → A(b(a(b(a(x)))))
A(a(a(x))) → A(b(b(x)))
A(a(a(x))) → B(b(x))
B(b(b(x))) → A(b(x))
A(a(a(x))) → B(x)
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(8) UsableRulesProof (EQUIVALENT transformation)
We can use the usable rules and reduction pair processor [LPAR04] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its arguments. Then, we can delete all non-usable rules [FROCOS05] from R.
(9) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(x)) → A(b(a(x)))
A(a(x)) → A(b(a(b(a(x)))))
A(a(a(x))) → A(b(b(x)))
A(a(a(x))) → B(b(x))
B(b(b(x))) → A(b(x))
A(a(a(x))) → B(x)
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(10) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
A(a(a(x))) → B(x)
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(a(x1)) = | | + | / | 0A | 0A | -I | \ |
| | 1A | 1A | 0A | | |
\ | 0A | 0A | -I | / |
| · | x1 |
POL(b(x1)) = | | + | / | 0A | -I | 0A | \ |
| | -I | -I | 0A | | |
\ | 1A | 0A | 0A | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
a(a(x)) → a(b(a(b(a(x)))))
a(a(a(x))) → a(b(b(x)))
b(b(b(x))) → a(b(x))
(11) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(x)) → A(b(a(x)))
A(a(x)) → A(b(a(b(a(x)))))
A(a(a(x))) → A(b(b(x)))
A(a(a(x))) → B(b(x))
B(b(b(x))) → A(b(x))
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(12) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
A(a(x)) → A(b(a(b(a(x)))))
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(a(x1)) = | | + | / | -I | 0A | -I | \ |
| | 0A | 0A | 0A | | |
\ | -I | -I | -I | / |
| · | x1 |
POL(b(x1)) = | | + | / | -I | 0A | 0A | \ |
| | -I | -I | 0A | | |
\ | 0A | -I | 0A | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
a(a(x)) → a(b(a(b(a(x)))))
a(a(a(x))) → a(b(b(x)))
b(b(b(x))) → a(b(x))
(13) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(x)) → A(b(a(x)))
A(a(a(x))) → A(b(b(x)))
A(a(a(x))) → B(b(x))
B(b(b(x))) → A(b(x))
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(14) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
A(a(x)) → A(b(a(x)))
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(a(x1)) = | | + | / | 0A | 0A | 0A | \ |
| | -I | -I | -I | | |
\ | -I | -I | -I | / |
| · | x1 |
POL(b(x1)) = | | + | / | -I | 0A | 0A | \ |
| | -I | 0A | 0A | | |
\ | 0A | 0A | 0A | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
a(a(x)) → a(b(a(b(a(x)))))
a(a(a(x))) → a(b(b(x)))
b(b(b(x))) → a(b(x))
(15) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(a(x))) → A(b(b(x)))
A(a(a(x))) → B(b(x))
B(b(b(x))) → A(b(x))
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(16) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
A(a(a(x))) → B(b(x))
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(a(x1)) = | | + | / | -I | -I | -I | \ |
| | 0A | 0A | 1A | | |
\ | 0A | 0A | 1A | / |
| · | x1 |
POL(b(x1)) = | | + | / | 0A | 0A | 0A | \ |
| | 1A | 0A | 0A | | |
\ | 1A | -I | -I | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
b(b(b(x))) → a(b(x))
a(a(x)) → a(b(a(b(a(x)))))
a(a(a(x))) → a(b(b(x)))
(17) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(a(x))) → A(b(b(x)))
B(b(b(x))) → A(b(x))
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(18) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node.
(19) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(a(a(x))) → A(b(b(x)))
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(20) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
A(a(a(x))) → A(b(b(x)))
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(a(x1)) = | | + | / | -I | -I | 0A | \ |
| | 0A | 0A | 0A | | |
\ | 0A | 0A | 1A | / |
| · | x1 |
POL(b(x1)) = | | + | / | 0A | 0A | 0A | \ |
| | 1A | 0A | 0A | | |
\ | 0A | -I | -I | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
b(b(b(x))) → a(b(x))
a(a(x)) → a(b(a(b(a(x)))))
a(a(a(x))) → a(b(b(x)))
(21) Obligation:
Q DP problem:
P is empty.
The TRS R consists of the following rules:
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(22) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(23) YES
(24) Obligation:
Q DP problem:
The TRS P consists of the following rules:
D(d(x)) → D(b(d(x)))
D(d(x)) → D(b(d(b(d(x)))))
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(25) UsableRulesProof (EQUIVALENT transformation)
We can use the usable rules and reduction pair processor [LPAR04] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its arguments. Then, we can delete all non-usable rules [FROCOS05] from R.
(26) Obligation:
Q DP problem:
The TRS P consists of the following rules:
D(d(x)) → D(b(d(x)))
D(d(x)) → D(b(d(b(d(x)))))
The TRS R consists of the following rules:
d(d(x)) → d(b(d(b(d(x)))))
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(27) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
D(d(x)) → D(b(d(x)))
D(d(x)) → D(b(d(b(d(x)))))
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial interpretation [POLO]:
POL(D(x1)) = x1
POL(a(x1)) = x1
POL(b(x1)) = 0
POL(d(x1)) = 1 + x1
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
b(b(b(x))) → a(b(x))
a(a(x)) → a(b(a(b(a(x)))))
a(a(a(x))) → a(b(b(x)))
(28) Obligation:
Q DP problem:
P is empty.
The TRS R consists of the following rules:
d(d(x)) → d(b(d(b(d(x)))))
b(b(b(x))) → a(b(x))
a(a(a(x))) → a(b(b(x)))
a(a(x)) → a(b(a(b(a(x)))))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(29) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(30) YES
(31) Obligation:
Q DP problem:
The TRS P consists of the following rules:
C(b(x)) → C(x)
C(a(x)) → C(x)
C(c(x)) → C(d(c(x)))
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(32) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
C(b(x)) → C(x)
C(a(x)) → C(x)
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial interpretation [POLO]:
POL(C(x1)) = x1
POL(a(x1)) = 1 + x1
POL(b(x1)) = 1 + x1
POL(c(x1)) = 1 + x1
POL(d(x1)) = 1
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
d(d(x)) → d(b(d(b(d(x)))))
(33) Obligation:
Q DP problem:
The TRS P consists of the following rules:
C(c(x)) → C(d(c(x)))
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(34) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
C(c(x)) → C(d(c(x)))
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial interpretation [POLO]:
POL(C(x1)) = x1
POL(a(x1)) = 0
POL(b(x1)) = x1
POL(c(x1)) = 1 + x1
POL(d(x1)) = 0
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
d(d(x)) → d(b(d(b(d(x)))))
(35) Obligation:
Q DP problem:
P is empty.
The TRS R consists of the following rules:
a(a(x)) → a(b(a(b(a(x)))))
c(a(x)) → a(b(a(a(c(x)))))
b(b(b(x))) → a(b(x))
c(b(x)) → a(a(c(x)))
d(d(x)) → d(b(d(b(d(x)))))
c(c(x)) → c(d(c(x)))
a(a(a(x))) → a(b(b(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(36) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(37) YES