InterestingExamples2.bpl(15,1): Error BP5001: This assertion might not hold.
Execution trace:
    InterestingExamples2.bpl(14,6): anon0
InterestingExamples2.bpl(16,1): Error BP5001: This assertion might not hold.
Execution trace:
    InterestingExamples2.bpl(14,6): anon0

Boogie program verifier finished with 0 verified, 2 errors