Termination of the given ITRSProblem could successfully be proven:



ITRS
  ↳ ITRStoIDPProof

ITRS problem:
The following domains are used:

z

The TRS R consists of the following rules:

g(TRUE, x, y, z) → f(>@z(x, z), x, y, +@z(z, 1@z))
g(TRUE, x, y, z) → f(>@z(x, z), x, +@z(y, 1@z), z)
f(TRUE, x, y, z) → g(>@z(x, y), x, y, z)

The set Q consists of the following terms:

g(TRUE, x0, x1, x2)
f(TRUE, x0, x1, x2)


Added dependency pairs

↳ ITRS
  ↳ ITRStoIDPProof
IDP
      ↳ UsableRulesProof

I DP problem:
The following domains are used:

z

The ITRS R consists of the following rules:

g(TRUE, x, y, z) → f(>@z(x, z), x, y, +@z(z, 1@z))
g(TRUE, x, y, z) → f(>@z(x, z), x, +@z(y, 1@z), z)
f(TRUE, x, y, z) → g(>@z(x, y), x, y, z)

The integer pair graph contains the following rules and edges:

(0): G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0])
(1): F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1])
(2): G(TRUE, x[2], y[2], z[2]) → F(>@z(x[2], z[2]), x[2], y[2], +@z(z[2], 1@z))

(0) -> (1), if ((z[0]* z[1])∧(x[0]* x[1])∧(+@z(y[0], 1@z) →* y[1])∧(>@z(x[0], z[0]) →* TRUE))


(1) -> (0), if ((z[1]* z[0])∧(x[1]* x[0])∧(y[1]* y[0])∧(>@z(x[1], y[1]) →* TRUE))


(1) -> (2), if ((z[1]* z[2])∧(x[1]* x[2])∧(y[1]* y[2])∧(>@z(x[1], y[1]) →* TRUE))


(2) -> (1), if ((+@z(z[2], 1@z) →* z[1])∧(x[2]* x[1])∧(y[2]* y[1])∧(>@z(x[2], z[2]) →* TRUE))



The set Q consists of the following terms:

g(TRUE, x0, x1, x2)
f(TRUE, x0, x1, x2)


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.

↳ ITRS
  ↳ ITRStoIDPProof
    ↳ IDP
      ↳ UsableRulesProof
IDP
          ↳ IDPNonInfProof

I DP problem:
The following domains are used:

z

R is empty.
The integer pair graph contains the following rules and edges:

(0): G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0])
(1): F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1])
(2): G(TRUE, x[2], y[2], z[2]) → F(>@z(x[2], z[2]), x[2], y[2], +@z(z[2], 1@z))

(0) -> (1), if ((z[0]* z[1])∧(x[0]* x[1])∧(+@z(y[0], 1@z) →* y[1])∧(>@z(x[0], z[0]) →* TRUE))


(1) -> (0), if ((z[1]* z[0])∧(x[1]* x[0])∧(y[1]* y[0])∧(>@z(x[1], y[1]) →* TRUE))


(1) -> (2), if ((z[1]* z[2])∧(x[1]* x[2])∧(y[1]* y[2])∧(>@z(x[1], y[1]) →* TRUE))


(2) -> (1), if ((+@z(z[2], 1@z) →* z[1])∧(x[2]* x[1])∧(y[2]* y[1])∧(>@z(x[2], z[2]) →* TRUE))



The set Q consists of the following terms:

g(TRUE, x0, x1, x2)
f(TRUE, x0, x1, x2)


The constraints were generated the following way:
The DP Problem is simplified using the Induction Calculus [NONINF] with the following steps:
Note that final constraints are written in bold face.


For Pair G(TRUE, x, y, z) → F(>@z(x, z), x, +@z(y, 1@z), z) the following chains were created:




For Pair F(TRUE, x, y, z) → G(>@z(x, y), x, y, z) the following chains were created:




For Pair G(TRUE, x, y, z) → F(>@z(x, z), x, y, +@z(z, 1@z)) the following chains were created:




To summarize, we get the following constraints P for the following pairs.



The constraints for P> respective Pbound are constructed from P where we just replace every occurence of "t ≥ s" in P by "t > s" respective "t ≥ c". Here c stands for the fresh constant used for Pbound.
Using the following integer polynomial ordering the resulting constraints can be solved
Polynomial interpretation over integers[POLO]:

POL(F(x1, x2, x3, x4)) = 1 + (-1)x4 + x2   
POL(TRUE) = -1   
POL(G(x1, x2, x3, x4)) = 1 + (-1)x4 + x2   
POL(+@z(x1, x2)) = x1 + x2   
POL(FALSE) = -1   
POL(1@z) = 1   
POL(undefined) = -1   
POL(>@z(x1, x2)) = -1   

The following pairs are in P>:

G(TRUE, x[2], y[2], z[2]) → F(>@z(x[2], z[2]), x[2], y[2], +@z(z[2], 1@z))

The following pairs are in Pbound:

G(TRUE, x[2], y[2], z[2]) → F(>@z(x[2], z[2]), x[2], y[2], +@z(z[2], 1@z))

The following pairs are in P:

G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0])
F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1])

At least the following rules have been oriented under context sensitive arithmetic replacement:

+@z1


↳ ITRS
  ↳ ITRStoIDPProof
    ↳ IDP
      ↳ UsableRulesProof
        ↳ IDP
          ↳ IDPNonInfProof
IDP
              ↳ IDPNonInfProof

I DP problem:
The following domains are used:

z

R is empty.
The integer pair graph contains the following rules and edges:

(0): G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0])
(1): F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1])

(1) -> (0), if ((z[1]* z[0])∧(x[1]* x[0])∧(y[1]* y[0])∧(>@z(x[1], y[1]) →* TRUE))


(0) -> (1), if ((z[0]* z[1])∧(x[0]* x[1])∧(+@z(y[0], 1@z) →* y[1])∧(>@z(x[0], z[0]) →* TRUE))



The set Q consists of the following terms:

g(TRUE, x0, x1, x2)
f(TRUE, x0, x1, x2)


The constraints were generated the following way:
The DP Problem is simplified using the Induction Calculus [NONINF] with the following steps:
Note that final constraints are written in bold face.


For Pair G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0]) the following chains were created:




For Pair F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1]) the following chains were created:




To summarize, we get the following constraints P for the following pairs.



The constraints for P> respective Pbound are constructed from P where we just replace every occurence of "t ≥ s" in P by "t > s" respective "t ≥ c". Here c stands for the fresh constant used for Pbound.
Using the following integer polynomial ordering the resulting constraints can be solved
Polynomial interpretation over integers[POLO]:

POL(F(x1, x2, x3, x4)) = 2 + (-1)x3 + x2   
POL(TRUE) = -1   
POL(G(x1, x2, x3, x4)) = 2 + (-1)x3 + x2   
POL(+@z(x1, x2)) = x1 + x2   
POL(FALSE) = -1   
POL(1@z) = 1   
POL(undefined) = -1   
POL(>@z(x1, x2)) = -1   

The following pairs are in P>:

G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0])

The following pairs are in Pbound:

G(TRUE, x[0], y[0], z[0]) → F(>@z(x[0], z[0]), x[0], +@z(y[0], 1@z), z[0])

The following pairs are in P:

F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1])

At least the following rules have been oriented under context sensitive arithmetic replacement:

+@z1


↳ ITRS
  ↳ ITRStoIDPProof
    ↳ IDP
      ↳ UsableRulesProof
        ↳ IDP
          ↳ IDPNonInfProof
            ↳ IDP
              ↳ IDPNonInfProof
IDP
                  ↳ IDependencyGraphProof

I DP problem:
The following domains are used:

z

R is empty.
The integer pair graph contains the following rules and edges:

(1): F(TRUE, x[1], y[1], z[1]) → G(>@z(x[1], y[1]), x[1], y[1], z[1])


The set Q consists of the following terms:

g(TRUE, x0, x1, x2)
f(TRUE, x0, x1, x2)


The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 1 less node.