(0) Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:
f(s(x)) → f(g(x, x))
g(0, 1) → s(0)
0 → 1
Q is empty.
(1) DependencyPairsProof (EQUIVALENT transformation)
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:
F(s(x)) → F(g(x, x))
F(s(x)) → G(x, x)
The TRS R consists of the following rules:
f(s(x)) → f(g(x, x))
g(0, 1) → s(0)
0 → 1
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(3) DependencyGraphProof (EQUIVALENT transformation)
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:
F(s(x)) → F(g(x, x))
The TRS R consists of the following rules:
f(s(x)) → f(g(x, x))
g(0, 1) → s(0)
0 → 1
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(5) UsableRulesReductionPairsProof (EQUIVALENT transformation)
By using the usable rules with reduction pair processor [LPAR04] with a polynomial ordering [POLO], all dependency pairs and the corresponding usable rules [FROCOS05] can be oriented non-strictly. All non-usable rules are removed, and those dependency pairs and usable rules that have been oriented strictly or contain non-usable symbols in their left-hand side are removed as well.
No dependency pairs are removed.
The following rules are removed from R:
f(s(x)) → f(g(x, x))
Used ordering: POLO with Polynomial interpretation [POLO]:
POL(0) = 0
POL(1) = 0
POL(F(x1)) = x1
POL(g(x1, x2)) = x1 + x2
POL(s(x1)) = 2·x1
(6) Obligation:
Q DP problem:
The TRS P consists of the following rules:
F(s(x)) → F(g(x, x))
The TRS R consists of the following rules:
g(0, 1) → s(0)
0 → 1
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(7) NonTerminationLoopProof (EQUIVALENT transformation)
We used the non-termination processor [FROCOS05] to show that the DP problem is infinite.
Found a loop by narrowing to the left:
s =
F(
g(
0,
0)) evaluates to t =
F(
g(
0,
0))
Thus s starts an infinite chain as s semiunifies with t with the following substitutions:
- Matcher: [ ]
- Semiunifier: [ ]
Rewriting sequenceF(g(0, 0)) →
F(
g(
0,
1))
with rule
0 →
1 at position [0,1] and matcher [ ]
F(g(0, 1)) →
F(
s(
0))
with rule
g(
0,
1) →
s(
0) at position [0] and matcher [ ]
F(s(0)) →
F(
g(
0,
0))
with rule
F(
s(
x)) →
F(
g(
x,
x))
Now applying the matcher to the start term leads to a term which is equal to the last term in the rewriting sequence
All these steps are and every following step will be a correct step w.r.t to Q.
(8) NO