(0) Obligation:

JBC Problem based on JBC Program:
Manifest-Version: 1.0 Created-By: 1.6.0_16 (Sun Microsystems Inc.) Main-Class: Factorial
/**
* The classical recursive definition of factorial.
*
* All calls terminate.
*
* Julia + BinTerm prove that all calls terminate
*
* Note that we have to express the basic case as n < 0
* in order to prove termination.
*
* @author <A HREF="mailto:fausto.spoto@univr.it">Fausto Spoto</A>
*/

public class Factorial {
public static int factorial(int n) {
if (n < 0) return 1;
else return n * factorial(n - 1);
}

public static void main(String[] args) {
factorial(10);
}
}

(1) JBCToGraph (SOUND transformation)

Constructed TerminationGraph.

(2) Obligation:

Termination Graph based on JBC Program:
Factorial.main([Ljava/lang/String;)V: Graph of 131 nodes with 0 SCCs.


(3) TerminationGraphToSCCProof (SOUND transformation)

Proven termination by absence of SCCs

(4) TRUE