(0) Obligation:

JBC Problem based on JBC Program:
public class Div extends Node {
public int length() {
return length();
}
}

public class Internal extends Node {
private Node next;

public Internal(Node next) {
this.next = next;
}

public int length() {
return 1 + next.length();
}
}

public class Nil extends Node {
public int length() {
return 0;
}
}

public abstract class Node {
public abstract int length();
}

/**
* An iteration over a list of <tt>Internal</tt> nodes ending with
* a terminating node <tt>Nil</tt>.
*
* All calls terminate.
*
* Julia + BinTerm prove that all calls terminate
*
* This example shows termination in the case of virtual calls
* to <tt>length()</tt>.
*
* @author <A HREF="mailto:fausto.spoto@univr.it">Fausto Spoto</A>
*/

public class Virtual {
public static void main(String[] args) {
Node d = new Div();
Node n = new Nil();
int l = 28; //Integer.parseInt(args[0]);
while (l-- > 0) n = new Internal(n);

n.length();
}
}

(1) JBCToGraph (SOUND transformation)

Constructed TerminationGraph.

(2) Obligation:

Termination Graph based on JBC Program:
Virtual.main([Ljava/lang/String;)V: Graph of 730 nodes with 0 SCCs.


(3) TerminationGraphToSCCProof (SOUND transformation)

Proven termination by absence of SCCs

(4) TRUE