Bug88.dfy(6,0): Error BP5003: A postcondition might not hold on this return path.
Bug88.dfy(5,12): Related location: This is the postcondition that might not hold.
Execution trace:
    (0,0): anon0
    Bug88.dfy(7,3): anon2_Else
Bug88.dfy(14,0): Error BP5003: A postcondition might not hold on this return path.
Bug88.dfy(13,10): Related location: This is the postcondition that might not hold.
Execution trace:
    (0,0): anon0

Dafny program verifier finished with 2 verified, 2 errors