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:

if(FALSE, u, v) → v
if(TRUE, u, v) → u
f(TRUE, x, y) → fNat(&&(>=@z(x, 0@z), >=@z(y, 0@z)), x, y)
fNat(TRUE, x, y) → f(>@z(x, y), x, round(+@z(y, 1@z)))
round(x) → if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))

The set Q consists of the following terms:

if(FALSE, x0, x1)
if(TRUE, x0, x1)
f(TRUE, x0, x1)
fNat(TRUE, x0, x1)
round(x0)


Added dependency pairs

↳ ITRS
  ↳ ITRStoIDPProof
IDP
      ↳ UsableRulesProof

I DP problem:
The following domains are used:

z

The ITRS R consists of the following rules:

if(FALSE, u, v) → v
if(TRUE, u, v) → u
f(TRUE, x, y) → fNat(&&(>=@z(x, 0@z), >=@z(y, 0@z)), x, y)
fNat(TRUE, x, y) → f(>@z(x, y), x, round(+@z(y, 1@z)))
round(x) → if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))

The integer pair graph contains the following rules and edges:

(0): FNAT(TRUE, x[0], y[0]) → F(>@z(x[0], y[0]), x[0], round(+@z(y[0], 1@z)))
(1): ROUND(x[1]) → IF(=@z(%@z(x[1], 2@z), 0@z), x[1], +@z(x[1], 1@z))
(2): FNAT(TRUE, x[2], y[2]) → ROUND(+@z(y[2], 1@z))
(3): F(TRUE, x[3], y[3]) → FNAT(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)), x[3], y[3])

(0) -> (3), if ((x[0]* x[3])∧(round(+@z(y[0], 1@z)) →* y[3])∧(>@z(x[0], y[0]) →* TRUE))


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


(3) -> (0), if ((x[3]* x[0])∧(y[3]* y[0])∧(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)) →* TRUE))


(3) -> (2), if ((x[3]* x[2])∧(y[3]* y[2])∧(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)) →* TRUE))



The set Q consists of the following terms:

if(FALSE, x0, x1)
if(TRUE, x0, x1)
f(TRUE, x0, x1)
fNat(TRUE, x0, x1)
round(x0)


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
          ↳ IDependencyGraphProof

I DP problem:
The following domains are used:

z

The ITRS R consists of the following rules:

if(FALSE, u, v) → v
if(TRUE, u, v) → u
round(x) → if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))

The integer pair graph contains the following rules and edges:

(0): FNAT(TRUE, x[0], y[0]) → F(>@z(x[0], y[0]), x[0], round(+@z(y[0], 1@z)))
(1): ROUND(x[1]) → IF(=@z(%@z(x[1], 2@z), 0@z), x[1], +@z(x[1], 1@z))
(2): FNAT(TRUE, x[2], y[2]) → ROUND(+@z(y[2], 1@z))
(3): F(TRUE, x[3], y[3]) → FNAT(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)), x[3], y[3])

(0) -> (3), if ((x[0]* x[3])∧(round(+@z(y[0], 1@z)) →* y[3])∧(>@z(x[0], y[0]) →* TRUE))


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


(3) -> (0), if ((x[3]* x[0])∧(y[3]* y[0])∧(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)) →* TRUE))


(3) -> (2), if ((x[3]* x[2])∧(y[3]* y[2])∧(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)) →* TRUE))



The set Q consists of the following terms:

if(FALSE, x0, x1)
if(TRUE, x0, x1)
f(TRUE, x0, x1)
fNat(TRUE, x0, x1)
round(x0)


The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 2 less nodes.

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

I DP problem:
The following domains are used:

z

The ITRS R consists of the following rules:

if(FALSE, u, v) → v
if(TRUE, u, v) → u
round(x) → if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))

The integer pair graph contains the following rules and edges:

(3): F(TRUE, x[3], y[3]) → FNAT(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)), x[3], y[3])
(0): FNAT(TRUE, x[0], y[0]) → F(>@z(x[0], y[0]), x[0], round(+@z(y[0], 1@z)))

(3) -> (0), if ((x[3]* x[0])∧(y[3]* y[0])∧(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)) →* TRUE))


(0) -> (3), if ((x[0]* x[3])∧(round(+@z(y[0], 1@z)) →* y[3])∧(>@z(x[0], y[0]) →* TRUE))



The set Q consists of the following terms:

if(FALSE, x0, x1)
if(TRUE, x0, x1)
f(TRUE, x0, x1)
fNat(TRUE, x0, x1)
round(x0)


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 F(TRUE, x[3], y[3]) → FNAT(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)), x[3], y[3]) the following chains were created:




For Pair FNAT(TRUE, x[0], y[0]) → F(>@z(x[0], y[0]), x[0], round(+@z(y[0], 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(0@z) = 0   
POL(TRUE) = -1   
POL(&&(x1, x2)) = -1   
POL(2@z) = 2   
POL(FALSE) = -1   
POL(F(x1, x2, x3)) = 1 + x2 + (-1)x3   
POL(>@z(x1, x2)) = 0   
POL(round(x1)) = x1   
POL(=@z(x1, x2)) = 0   
POL(if(x1, x2, x3)) = (-1)max{(-1)x2, (-1)x3}   
POL(>=@z(x1, x2)) = -1   
POL(+@z(x1, x2)) = x1 + x2   
POL(1@z) = 1   
POL(undefined) = -1   
POL(FNAT(x1, x2, x3)) = 2 + (2)x1 + x2 + (-1)x3   

The following pairs are in P>:

F(TRUE, x[3], y[3]) → FNAT(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)), x[3], y[3])

The following pairs are in Pbound:

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

The following pairs are in P:

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

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

&&(FALSE, FALSE)1FALSE1
v1if(FALSE, u, v)1
u1if(TRUE, u, v)1
+@z1
&&(TRUE, TRUE)1TRUE1
&&(FALSE, TRUE)1FALSE1
&&(TRUE, FALSE)1FALSE1
if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))1round(x)1
%@z1


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

I DP problem:
The following domains are used:

z

The ITRS R consists of the following rules:

if(FALSE, u, v) → v
if(TRUE, u, v) → u
round(x) → if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))

The integer pair graph contains the following rules and edges:

(3): F(TRUE, x[3], y[3]) → FNAT(&&(>=@z(x[3], 0@z), >=@z(y[3], 0@z)), x[3], y[3])


The set Q consists of the following terms:

if(FALSE, x0, x1)
if(TRUE, x0, x1)
f(TRUE, x0, x1)
fNat(TRUE, x0, x1)
round(x0)


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

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

I DP problem:
The following domains are used:

z

The ITRS R consists of the following rules:

if(FALSE, u, v) → v
if(TRUE, u, v) → u
round(x) → if(=@z(%@z(x, 2@z), 0@z), x, +@z(x, 1@z))

The integer pair graph contains the following rules and edges:

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


The set Q consists of the following terms:

if(FALSE, x0, x1)
if(TRUE, x0, x1)
f(TRUE, x0, x1)
fNat(TRUE, x0, x1)
round(x0)


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