Termination of the given JBC could be disproven:

(0) Obligation:

JBC Problem based on JBC Program:
Manifest-Version: 1.0 Created-By: 1.6.0_26 (Sun Microsystems Inc.) Main-Class: simple/fib/Main

package simple.fib;

public class Fibonacci {

	public static void fib(int n) {
		int i = 0;
		int j = 1;
		int t = 0;
		while (j != n) {
			t = j+i;
			i = j;
			j = t;
		}
	}
}


package simple.fib;

public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Fibonacci.fib(args.length);
	}

}

(1) JBCNonTerm (EQUIVALENT transformation)

Reached a loop using the following run:
0:

<simple.fib.Main.main||0: load ADDR args||args: a100|| ->
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

1:

<simple.fib.Main.main||1: arraylength|| - ||a100>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

2:

<simple.fib.Main.main||2: simple.fib.Fibonacci.fib(I)V|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

3:

<simple.fib.Fibonacci.fib||0: push 0||n: 0|| ->
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

4:

<simple.fib.Fibonacci.fib||1: store INT to i||n: 0||0>
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

5:

<simple.fib.Fibonacci.fib||2: push 1||n: 0, i: 0|| ->
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

6:

<simple.fib.Fibonacci.fib||3: store INT to j||n: 0, i: 0||1>
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

7:

<simple.fib.Fibonacci.fib||4: push 0||n: 0, i: 0, j: 1|| ->
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

8:

<simple.fib.Fibonacci.fib||5: store INT to t||n: 0, i: 0, j: 1||0>
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

9:

<simple.fib.Fibonacci.fib||6: load INT j||n: 0, i: 0, j: 1|| ->
<simple.fib.Main.main||2: simple.fib.Fibonacci.fib|| - ||0>
	String.serialVersionUID: -6849794470754667710L
	String.serialPersistentFields: a98
	String.CASE_INSENSITIVE_ORDER: o50
	String$CaseInsensitiveComparator.serialVersionUID: 8575799808933029326L
	RuntimeException.serialVersionUID: -7034897190745766939L
	Exception.serialVersionUID: -3387516993124229948L
	Throwable.serialVersionUID: -3042686055658047285L
	o50!: String$CaseInsensitiveComparator()
	a98([java.io.ObjectStreamField|]): length 0
	a100([java.lang.String...]): length 0

In the loop head node, references [i32, i16] were interesting.
By SMT, we could prove
((0 <= initial_i16 and 0 <= initial_i31 and 1 <= initial_i32) and (((path1_i37 = (path1_i32 + path1_i31) and path1_i16 = res_i16 and path1_i32 = res_i31 and path1_i37 = res_i32 and path1_i16 = initial_i16 and path1_i31 = initial_i31 and path1_i32 = initial_i32) and path1_i32 > path1_i16) and (res_i37 = (res_i32 + res_i31) and !res_i32 != res_i16)))
to be UNSAT. Consequently, the loop will not terminate.

(2) NO