(0) Obligation:

JBC Problem based on JBC Program:
Manifest-Version: 1.0 Created-By: 1.6.0_16 (Sun Microsystems Inc.) Main-Class: PastaB5
/**
* Example taken from "A Term Rewriting Approach to the Automated Termination
* Analysis of Imperative Programs" (http://www.cs.unm.edu/~spf/papers/2009-02.pdf)
* and converted to Java.
*/

public class PastaB5 {
public static void main(String[] args) {
Random.args = args;
int x = Random.random();

while (x > 0 && (x % 2) == 0) {
x--;
}
}
}


public class Random {
static String[] args;
static int index = 0;

public static int random() {
String string = args[index];
index++;
return string.length();
}
}


(1) JBC2FIG (SOUND transformation)

Constructed FIGraph.

(2) Obligation:

FIGraph based on JBC Program:
PastaB5.main([Ljava/lang/String;)V: Graph of 92 nodes with 1 SCC.


(3) FIGtoITRSProof (SOUND transformation)

Transformed FIGraph SCCs to IDPs. Logs:


Log for SCC 0:

Generated 11 rules for P and 5 rules for R.


Combined rules. Obtained 1 rules for P and 1 rules for R.


Filtered ground terms:


118_0_main_LE(x1, x2, x3) → 118_0_main_LE(x2, x3)
Cond_118_0_main_LE(x1, x2, x3, x4) → Cond_118_0_main_LE(x1, x3, x4)
135_0_main_Return(x1) → 135_0_main_Return

Filtered duplicate args:


118_0_main_LE(x1, x2) → 118_0_main_LE(x2)
Cond_118_0_main_LE(x1, x2, x3) → Cond_118_0_main_LE(x1, x3)

Combined rules. Obtained 1 rules for P and 1 rules for R.


Finished conversion. Obtained 1 rules for P and 1 rules for R. System has predefined symbols.


(4) Obligation:

IDP problem:
The following function symbols are pre-defined:
!=~Neq: (Integer, Integer) -> Boolean
*~Mul: (Integer, Integer) -> Integer
>=~Ge: (Integer, Integer) -> Boolean
-1~UnaryMinus: (Integer) -> Integer
|~Bwor: (Integer, Integer) -> Integer
/~Div: (Integer, Integer) -> Integer
=~Eq: (Integer, Integer) -> Boolean
~Bwxor: (Integer, Integer) -> Integer
||~Lor: (Boolean, Boolean) -> Boolean
!~Lnot: (Boolean) -> Boolean
<~Lt: (Integer, Integer) -> Boolean
-~Sub: (Integer, Integer) -> Integer
<=~Le: (Integer, Integer) -> Boolean
>~Gt: (Integer, Integer) -> Boolean
~~Bwnot: (Integer) -> Integer
%~Mod: (Integer, Integer) -> Integer
&~Bwand: (Integer, Integer) -> Integer
+~Add: (Integer, Integer) -> Integer
&&~Land: (Boolean, Boolean) -> Boolean


The following domains are used:

Boolean, Integer


The ITRS R consists of the following rules:
118_0_main_LE(0) → 135_0_main_Return

The integer pair graph contains the following rules and edges:
(0): 118_0_MAIN_LE(x0[0]) → COND_118_0_MAIN_LE(x0[0] > 0 && 0 = x0[0] % 2, x0[0])
(1): COND_118_0_MAIN_LE(TRUE, x0[1]) → 118_0_MAIN_LE(x0[1] + -1)

(0) -> (1), if ((x0[0] > 0 && 0 = x0[0] % 2* TRUE)∧(x0[0]* x0[1]))


(1) -> (0), if ((x0[1] + -1* x0[0]))



The set Q consists of the following terms:
118_0_main_LE(0)

(5) IDPNonInfProof (SOUND transformation)

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 118_0_MAIN_LE(x0) → COND_118_0_MAIN_LE(&&(>(x0, 0), =(0, %(x0, 2))), x0) the following chains were created:
  • We consider the chain 118_0_MAIN_LE(x0[0]) → COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0]), COND_118_0_MAIN_LE(TRUE, x0[1]) → 118_0_MAIN_LE(+(x0[1], -1)) which results in the following constraint:

    (1)    (&&(>(x0[0], 0), =(0, %(x0[0], 2)))=TRUEx0[0]=x0[1]118_0_MAIN_LE(x0[0])≥NonInfC∧118_0_MAIN_LE(x0[0])≥COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])∧(UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥))



    We simplified constraint (1) using rules (IV), (IDP_BOOLEAN) which results in the following new constraint:

    (2)    (>(x0[0], 0)=TRUE>=(0, %(x0[0], 2))=TRUE<=(0, %(x0[0], 2))=TRUE118_0_MAIN_LE(x0[0])≥NonInfC∧118_0_MAIN_LE(x0[0])≥COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])∧(UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥))



    We simplified constraint (2) using rule (POLY_CONSTRAINTS) which results in the following new constraint:

    (3)    (x0[0] + [-1] ≥ 0∧[-1]min{[2], [-2]} ≥ 0∧max{[2], [-2]} ≥ 0 ⇒ (UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥)∧[(-1)Bound*bni_12] + [(2)bni_12]x0[0] ≥ 0∧[(-1)bso_13] ≥ 0)



    We simplified constraint (3) using rule (IDP_POLY_SIMPLIFY) which results in the following new constraint:

    (4)    (x0[0] + [-1] ≥ 0∧[-1]min{[2], [-2]} ≥ 0∧max{[2], [-2]} ≥ 0 ⇒ (UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥)∧[(-1)Bound*bni_12] + [(2)bni_12]x0[0] ≥ 0∧[(-1)bso_13] ≥ 0)



    We simplified constraint (4) using rule (POLY_REMOVE_MIN_MAX) which results in the following new constraint:

    (5)    (x0[0] + [-1] ≥ 0∧[4] ≥ 0∧[2] ≥ 0∧[2] ≥ 0 ⇒ (UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥)∧[(-1)Bound*bni_12] + [(2)bni_12]x0[0] ≥ 0∧[(-1)bso_13] ≥ 0)



    We simplified constraint (5) using rule (IDP_SMT_SPLIT) which results in the following new constraint:

    (6)    (x0[0] ≥ 0∧[4] ≥ 0∧[2] ≥ 0∧[2] ≥ 0 ⇒ (UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥)∧[(-1)Bound*bni_12 + (2)bni_12] + [(2)bni_12]x0[0] ≥ 0∧[(-1)bso_13] ≥ 0)



    We simplified constraint (6) using rule (IDP_POLY_GCD) which results in the following new constraint:

    (7)    (x0[0] ≥ 0∧[1] ≥ 0∧[1] ≥ 0∧[1] ≥ 0 ⇒ (UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥)∧[(-1)Bound*bni_12 + (2)bni_12] + [(2)bni_12]x0[0] ≥ 0∧[(-1)bso_13] ≥ 0)







For Pair COND_118_0_MAIN_LE(TRUE, x0) → 118_0_MAIN_LE(+(x0, -1)) the following chains were created:
  • We consider the chain COND_118_0_MAIN_LE(TRUE, x0[1]) → 118_0_MAIN_LE(+(x0[1], -1)) which results in the following constraint:

    (8)    (COND_118_0_MAIN_LE(TRUE, x0[1])≥NonInfC∧COND_118_0_MAIN_LE(TRUE, x0[1])≥118_0_MAIN_LE(+(x0[1], -1))∧(UIncreasing(118_0_MAIN_LE(+(x0[1], -1))), ≥))



    We simplified constraint (8) using rule (POLY_CONSTRAINTS) which results in the following new constraint:

    (9)    ((UIncreasing(118_0_MAIN_LE(+(x0[1], -1))), ≥)∧[2 + (-1)bso_15] ≥ 0)



    We simplified constraint (9) using rule (IDP_POLY_SIMPLIFY) which results in the following new constraint:

    (10)    ((UIncreasing(118_0_MAIN_LE(+(x0[1], -1))), ≥)∧[2 + (-1)bso_15] ≥ 0)



    We simplified constraint (10) using rule (POLY_REMOVE_MIN_MAX) which results in the following new constraint:

    (11)    ((UIncreasing(118_0_MAIN_LE(+(x0[1], -1))), ≥)∧[2 + (-1)bso_15] ≥ 0)



    We simplified constraint (11) using rule (IDP_UNRESTRICTED_VARS) which results in the following new constraint:

    (12)    ((UIncreasing(118_0_MAIN_LE(+(x0[1], -1))), ≥)∧0 = 0∧[2 + (-1)bso_15] ≥ 0)







To summarize, we get the following constraints P for the following pairs.
  • 118_0_MAIN_LE(x0) → COND_118_0_MAIN_LE(&&(>(x0, 0), =(0, %(x0, 2))), x0)
    • (x0[0] ≥ 0∧[1] ≥ 0∧[1] ≥ 0∧[1] ≥ 0 ⇒ (UIncreasing(COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])), ≥)∧[(-1)Bound*bni_12 + (2)bni_12] + [(2)bni_12]x0[0] ≥ 0∧[(-1)bso_13] ≥ 0)

  • COND_118_0_MAIN_LE(TRUE, x0) → 118_0_MAIN_LE(+(x0, -1))
    • ((UIncreasing(118_0_MAIN_LE(+(x0[1], -1))), ≥)∧0 = 0∧[2 + (-1)bso_15] ≥ 0)




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(TRUE) = 0   
POL(FALSE) = 0   
POL(118_0_main_LE(x1)) = [-1]   
POL(0) = 0   
POL(135_0_main_Return) = [-1]   
POL(118_0_MAIN_LE(x1)) = [2]x1   
POL(COND_118_0_MAIN_LE(x1, x2)) = [2]x2   
POL(&&(x1, x2)) = [-1]   
POL(>(x1, x2)) = [-1]   
POL(=(x1, x2)) = [-1]   
POL(2) = [2]   
POL(+(x1, x2)) = x1 + x2   
POL(-1) = [-1]   

Polynomial Interpretations with Context Sensitive Arithemetic Replacement
POL(TermCSAR-Mode @ Context)

POL(%(x1, 2)-1 @ {}) = min{x2, [-1]x2}   
POL(%(x1, 2)1 @ {}) = max{x2, [-1]x2}   

The following pairs are in P>:

COND_118_0_MAIN_LE(TRUE, x0[1]) → 118_0_MAIN_LE(+(x0[1], -1))

The following pairs are in Pbound:

118_0_MAIN_LE(x0[0]) → COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])

The following pairs are in P:

118_0_MAIN_LE(x0[0]) → COND_118_0_MAIN_LE(&&(>(x0[0], 0), =(0, %(x0[0], 2))), x0[0])

There are no usable rules.

(6) Complex Obligation (AND)

(7) Obligation:

IDP problem:
The following function symbols are pre-defined:
!=~Neq: (Integer, Integer) -> Boolean
*~Mul: (Integer, Integer) -> Integer
>=~Ge: (Integer, Integer) -> Boolean
-1~UnaryMinus: (Integer) -> Integer
|~Bwor: (Integer, Integer) -> Integer
/~Div: (Integer, Integer) -> Integer
=~Eq: (Integer, Integer) -> Boolean
~Bwxor: (Integer, Integer) -> Integer
||~Lor: (Boolean, Boolean) -> Boolean
!~Lnot: (Boolean) -> Boolean
<~Lt: (Integer, Integer) -> Boolean
-~Sub: (Integer, Integer) -> Integer
<=~Le: (Integer, Integer) -> Boolean
>~Gt: (Integer, Integer) -> Boolean
~~Bwnot: (Integer) -> Integer
%~Mod: (Integer, Integer) -> Integer
&~Bwand: (Integer, Integer) -> Integer
+~Add: (Integer, Integer) -> Integer
&&~Land: (Boolean, Boolean) -> Boolean


The following domains are used:

Boolean, Integer


The ITRS R consists of the following rules:
118_0_main_LE(0) → 135_0_main_Return

The integer pair graph contains the following rules and edges:
(0): 118_0_MAIN_LE(x0[0]) → COND_118_0_MAIN_LE(x0[0] > 0 && 0 = x0[0] % 2, x0[0])


The set Q consists of the following terms:
118_0_main_LE(0)

(8) IDependencyGraphProof (EQUIVALENT transformation)

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

(9) TRUE

(10) Obligation:

IDP problem:
The following function symbols are pre-defined:
!=~Neq: (Integer, Integer) -> Boolean
*~Mul: (Integer, Integer) -> Integer
>=~Ge: (Integer, Integer) -> Boolean
-1~UnaryMinus: (Integer) -> Integer
|~Bwor: (Integer, Integer) -> Integer
/~Div: (Integer, Integer) -> Integer
=~Eq: (Integer, Integer) -> Boolean
~Bwxor: (Integer, Integer) -> Integer
||~Lor: (Boolean, Boolean) -> Boolean
!~Lnot: (Boolean) -> Boolean
<~Lt: (Integer, Integer) -> Boolean
-~Sub: (Integer, Integer) -> Integer
<=~Le: (Integer, Integer) -> Boolean
>~Gt: (Integer, Integer) -> Boolean
~~Bwnot: (Integer) -> Integer
%~Mod: (Integer, Integer) -> Integer
&~Bwand: (Integer, Integer) -> Integer
+~Add: (Integer, Integer) -> Integer
&&~Land: (Boolean, Boolean) -> Boolean


The following domains are used:

Integer


The ITRS R consists of the following rules:
118_0_main_LE(0) → 135_0_main_Return

The integer pair graph contains the following rules and edges:
(1): COND_118_0_MAIN_LE(TRUE, x0[1]) → 118_0_MAIN_LE(x0[1] + -1)


The set Q consists of the following terms:
118_0_main_LE(0)

(11) IDependencyGraphProof (EQUIVALENT transformation)

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

(12) TRUE