Assignment computed by Houdini:
b1 = True
b2 = True
b3 = True
houd10.bpl(17,3): Error BP5002: A precondition for this call might not hold.
houd10.bpl(22,1): Related location: This is the precondition that might not hold.
Execution trace:
    houd10.bpl(16,9): anon0

Boogie program verifier finished with 0 verified, 1 error