(0) Obligation:

JBC Problem based on JBC Program:
/**
* 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 PastaA8 {
public static void main(String[] args) {
Random.args = args;
int x = Random.random();
int y = Random.random();

while (x > y) {
x++;
y += 2;
}
}
}


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

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


(1) JBCToGraph (SOUND transformation)

Constructed TerminationGraph.

(2) Obligation:

Termination Graph based on JBC Program:
PastaA8.main([Ljava/lang/String;)V: Graph of 175 nodes with 1 SCC.


(3) TerminationGraphToSCCProof (SOUND transformation)

Splitted TerminationGraph to 1 SCCs.

(4) Obligation:

SCC of termination graph based on JBC Program.
SCC contains nodes from the following methods: PastaA8.main([Ljava/lang/String;)V
SCC calls the following helper methods:
Performed SCC analyses:
  • Used field analysis yielded the following read fields:
  • Marker field analysis yielded the following relations that could be markers:

(5) SCCToIntTRSProof (SOUND transformation)

Transformed FIGraph SCCs to intTRSs. Log:

Generated rules. Obtained 8 IRules

P rules:
f314_0_main_Load(EOS, i18, i45, i18) → f321_0_main_LE(EOS, i18, i45, i18, i45)
f321_0_main_LE(EOS, i18, i45, i18, i45) → f340_0_main_LE(EOS, i18, i45, i18, i45)
f340_0_main_LE(EOS, i18, i45, i18, i45) → f353_0_main_Inc(EOS, i18, i45) | >(i18, i45)
f353_0_main_Inc(EOS, i18, i45) → f363_0_main_Inc(EOS, +(i18, 1), i45) | >=(i18, 0)
f363_0_main_Inc(EOS, i54, i45) → f377_0_main_JMP(EOS, i54, +(i45, 2)) | >=(i45, 0)
f377_0_main_JMP(EOS, i54, i58) → f420_0_main_Load(EOS, i54, i58)
f420_0_main_Load(EOS, i54, i58) → f306_0_main_Load(EOS, i54, i58)
f306_0_main_Load(EOS, i18, i45) → f314_0_main_Load(EOS, i18, i45, i18)

Combined rules. Obtained 1 IRules

P rules:
f314_0_main_Load(EOS, x0, x1, x0) → f314_0_main_Load(EOS, +(x0, 1), +(x1, 2), +(x0, 1)) | &&(&&(>(+(x1, 1), 0), >(+(x0, 1), 0)), <(x1, x0))

Filtered ground terms:


f314_0_main_Load(x1, x2, x3, x4) → f314_0_main_Load(x2, x3, x4)
Cond_f314_0_main_Load(x1, x2, x3, x4, x5) → Cond_f314_0_main_Load(x1, x3, x4, x5)

Filtered duplicate terms:


f314_0_main_Load(x1, x2, x3) → f314_0_main_Load(x2, x3)
Cond_f314_0_main_Load(x1, x2, x3, x4) → Cond_f314_0_main_Load(x1, x3, x4)

Prepared 1 rules for path length conversion:

P rules:
f314_0_main_Load(x1, x0) → f314_0_main_Load(+(x1, 2), +(x0, 1)) | &&(&&(>(+(x1, 1), 0), >(+(x0, 1), 0)), <(x1, x0))

Finished conversion. Obtained 1 rules.

P rules:
f314_0_main_Load(x0, x1) → f314_0_main_Load(+(x0, 2), +(x1, 1)) | &&(&&(>(x1, x0), >(x0, -1)), >(x1, -1))

(6) Obligation:

Rules:
f314_0_main_Load(x0, x1) → f314_0_main_Load(+(x0, 2), +(x1, 1)) | &&(&&(>(x1, x0), >(x0, -1)), >(x1, -1))

(7) PolynomialOrderProcessor (EQUIVALENT transformation)

Found the following polynomial interpretation:


[f314_0_main_Load(x3, x5)] = -x3 + x5

Therefore the following rule(s) have been dropped:


f314_0_main_Load(x0, x1) → f314_0_main_Load(+(x0, 2), +(x1, 1)) | &&(&&(>(x1, x0), >(x0, -1)), >(x1, -1))

(8) YES