(0) Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:
a(a(x)) → b(b(x))
c(c(b(x))) → d(c(a(x)))
a(x) → d(c(c(x)))
c(d(x)) → b(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(a(x)) → b(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
d(c(x)) → c(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)) → B(b(x))
A(a(x)) → B(x)
B(c(c(x))) → A(c(d(x)))
B(c(c(x))) → D(x)
A(x) → D(x)
D(c(x)) → B(x)
The TRS R consists of the following rules:
a(a(x)) → b(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
d(c(x)) → c(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 1 SCC with 2 less nodes.
(6) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(x) → D(x)
D(c(x)) → B(x)
B(c(c(x))) → A(c(d(x)))
B(c(c(x))) → D(x)
The TRS R consists of the following rules:
a(a(x)) → b(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
d(c(x)) → c(b(x))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(7) 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.
(8) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(x) → D(x)
D(c(x)) → B(x)
B(c(c(x))) → A(c(d(x)))
B(c(c(x))) → D(x)
The TRS R consists of the following rules:
d(c(x)) → c(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(9) MNOCProof (EQUIVALENT transformation)
We use the modular non-overlap check [LPAR04] to enlarge Q to all left-hand sides of R.
(10) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(x) → D(x)
D(c(x)) → B(x)
B(c(c(x))) → A(c(d(x)))
B(c(c(x))) → D(x)
The TRS R consists of the following rules:
d(c(x)) → c(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
The set Q consists of the following terms:
d(c(x0))
b(c(c(x0)))
a(x0)
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.
B(c(c(x))) → D(x)
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(c(x1)) = | | + | / | 0A | 0A | 1A | \ |
| | 0A | 0A | -I | | |
\ | -I | 0A | 0A | / |
| · | x1 |
POL(d(x1)) = | | + | / | 0A | 0A | 1A | \ |
| | -I | -I | 0A | | |
\ | -I | -I | 0A | / |
| · | x1 |
POL(b(x1)) = | | + | / | -I | 0A | 0A | \ |
| | -I | 0A | 0A | | |
\ | -I | 0A | 0A | / |
| · | x1 |
POL(a(x1)) = | | + | / | 0A | 0A | 1A | \ |
| | 0A | 0A | 1A | | |
\ | 0A | 0A | 1A | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
d(c(x)) → c(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
(12) Obligation:
Q DP problem:
The TRS P consists of the following rules:
A(x) → D(x)
D(c(x)) → B(x)
B(c(c(x))) → A(c(d(x)))
The TRS R consists of the following rules:
d(c(x)) → c(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
The set Q consists of the following terms:
d(c(x0))
b(c(c(x0)))
a(x0)
We have to consider all minimal (P,Q,R)-chains.
(13) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04,JAR06].
The following pairs can be oriented strictly and are deleted.
A(x) → D(x)
The remaining pairs can at least be oriented weakly.
Used ordering: Matrix interpretation [MATRO] with arctic natural numbers [ARCTIC]:
POL(c(x1)) = | | + | / | 0A | 0A | 0A | \ |
| | 0A | 0A | 1A | | |
\ | 0A | -I | 0A | / |
| · | x1 |
POL(d(x1)) = | | + | / | -I | -I | 0A | \ |
| | -I | 0A | 1A | | |
\ | -I | -I | 0A | / |
| · | x1 |
POL(b(x1)) = | | + | / | 0A | -I | -I | \ |
| | 0A | -I | 0A | | |
\ | 0A | -I | 0A | / |
| · | x1 |
POL(a(x1)) = | | + | / | 0A | 0A | 1A | \ |
| | -I | 0A | 1A | | |
\ | -I | 0A | 1A | / |
| · | x1 |
The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented:
d(c(x)) → c(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
(14) Obligation:
Q DP problem:
The TRS P consists of the following rules:
D(c(x)) → B(x)
B(c(c(x))) → A(c(d(x)))
The TRS R consists of the following rules:
d(c(x)) → c(b(x))
b(c(c(x))) → a(c(d(x)))
a(x) → c(c(d(x)))
The set Q consists of the following terms:
d(c(x0))
b(c(c(x0)))
a(x0)
We have to consider all minimal (P,Q,R)-chains.
(15) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 2 less nodes.
(16) TRUE