YES
proof of /export/starexec/sandbox/benchmark/theBenchmark.xml
# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty


Termination w.r.t. Q of the given QTRS could be proven:

(0) QTRS
(1) DependencyPairsProof [EQUIVALENT, 0 ms]
(2) QDP
(3) DependencyGraphProof [EQUIVALENT, 1 ms]
(4) QDP
(5) QDPOrderProof [EQUIVALENT, 363 ms]
(6) QDP
(7) UsableRulesProof [EQUIVALENT, 0 ms]
(8) QDP
(9) QDPSizeChangeProof [EQUIVALENT, 0 ms]
(10) YES


----------------------------------------

(0)
Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:

   a(a(x1)) -> x1
   b(b(x1)) -> c(c(c(x1)))
   b(c(x1)) -> a(b(b(x1)))

Q is empty.

----------------------------------------

(1) DependencyPairsProof (EQUIVALENT)
Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.
----------------------------------------

(2)
Obligation:
Q DP problem:
The TRS P consists of the following rules:

   B(c(x1)) -> A(b(b(x1)))
   B(c(x1)) -> B(b(x1))
   B(c(x1)) -> B(x1)

The TRS R consists of the following rules:

   a(a(x1)) -> x1
   b(b(x1)) -> c(c(c(x1)))
   b(c(x1)) -> a(b(b(x1)))

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

(3) DependencyGraphProof (EQUIVALENT)
The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node.
----------------------------------------

(4)
Obligation:
Q DP problem:
The TRS P consists of the following rules:

   B(c(x1)) -> B(x1)
   B(c(x1)) -> B(b(x1))

The TRS R consists of the following rules:

   a(a(x1)) -> x1
   b(b(x1)) -> c(c(c(x1)))
   b(c(x1)) -> a(b(b(x1)))

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

(5) QDPOrderProof (EQUIVALENT)
We use the reduction pair processor [LPAR04,JAR06].


The following pairs can be oriented strictly and are deleted.

   B(c(x1)) -> B(b(x1))
The remaining pairs can at least be oriented weakly.
Used ordering:  Matrix interpretation [MATRO] with arctic integers [ARCTIC,STERNAGEL_THIEMANN_RTA14]:

   <<<
 POL(B(x_1)) =  	[[0A]] 	 +  	[[-1A, -1A, -1A]] 	* 	x_1
>>>

   <<<
 POL(c(x_1)) =  	[[2A], [-I], [0A]] 	 +  	[[0A, -1A, 0A], [-I, -1A, -I], [-I, 2A, -I]] 	* 	x_1
>>>

   <<<
 POL(b(x_1)) =  	[[0A], [1A], [-I]] 	 +  	[[-1A, 1A, -1A], [-1A, 1A, -1A], [-1A, -1A, -1A]] 	* 	x_1
>>>

   <<<
 POL(a(x_1)) =  	[[0A], [-I], [-I]] 	 +  	[[-1A, -1A, 1A], [-1A, -1A, 1A], [-1A, -1A, -1A]] 	* 	x_1
>>>


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

   b(b(x1)) -> c(c(c(x1)))
   b(c(x1)) -> a(b(b(x1)))
   a(a(x1)) -> x1


----------------------------------------

(6)
Obligation:
Q DP problem:
The TRS P consists of the following rules:

   B(c(x1)) -> B(x1)

The TRS R consists of the following rules:

   a(a(x1)) -> x1
   b(b(x1)) -> c(c(c(x1)))
   b(c(x1)) -> a(b(b(x1)))

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

(7) UsableRulesProof (EQUIVALENT)
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:

   B(c(x1)) -> B(x1)

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

(9) QDPSizeChangeProof (EQUIVALENT)
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(c(x1)) -> B(x1)
The graph contains the following edges 1 > 1


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(10)
YES