InterestingExamples1.bpl(22,3): Error BP5001: This assertion might not hold.
Execution trace:
    InterestingExamples1.bpl(19,5): anon0
InterestingExamples1.bpl(28,3): Error BP5001: This assertion might not hold.
Execution trace:
    InterestingExamples1.bpl(19,5): anon0

Boogie program verifier finished with 0 verified, 2 errors