FunctionSpecifications.dfy(35,24): Error: a postcondition could not be proved on this return path
FunctionSpecifications.dfy(31,12): Related location: this is the postcondition that could not be proved
FunctionSpecifications.dfy(45,2): Error: a postcondition could not be proved on this return path
FunctionSpecifications.dfy(40,23): Related location: this is the postcondition that could not be proved
FunctionSpecifications.dfy(61,10): Error: cannot prove termination; try supplying a decreases clause
FunctionSpecifications.dfy(68,15): Error: a postcondition could not be proved on this return path
FunctionSpecifications.dfy(69,21): Related location: this is the postcondition that could not be proved
FunctionSpecifications.dfy(117,22): Error: assertion might not hold
FunctionSpecifications.dfy(120,22): Error: assertion might not hold
FunctionSpecifications.dfy(135,26): Error: assertion might not hold
FunctionSpecifications.dfy(139,26): Error: assertion might not hold
FunctionSpecifications.dfy(144,25): Error: a postcondition could not be proved on this return path
FunctionSpecifications.dfy(146,28): Related location: this is the postcondition that could not be proved
FunctionSpecifications.dfy(155,2): Error: decreases clause might not decrease
FunctionSpecifications.dfy(162,2): Error: decreases clause might not decrease
FunctionSpecifications.dfy(167,2): Error: cannot prove termination; try supplying a decreases clause

Dafny program verifier finished with 10 verified, 12 errors
