Datatypes.dfy(297,9): Error BP5003: A postcondition might not hold on this return path.
Datatypes.dfy(295,14): Related location: This is the postcondition that might not hold.
Execution trace:
    (0,0): anon0
    (0,0): anon13_Then
    (0,0): anon14_Else
    (0,0): anon15_Then
    (0,0): anon6
Datatypes.dfy(298,11): Error: missing case in case statement: Appendix
Execution trace:
    (0,0): anon0
    (0,0): anon13_Then
    (0,0): anon14_Else
    (0,0): anon15_Else
    (0,0): anon16_Then
Datatypes.dfy(349,4): Error: missing case in case statement: Cons
Execution trace:
    (0,0): anon0
    (0,0): anon7_Else
    (0,0): anon8_Then
Datatypes.dfy(349,4): Error: missing case in case statement: Nil
Execution trace:
    (0,0): anon0
    (0,0): anon7_Else
    (0,0): anon8_Else
    (0,0): anon9_Then
Datatypes.dfy(356,7): Error: missing case in case statement: Cons
Execution trace:
    (0,0): anon0
    (0,0): anon10_Else
    (0,0): anon11_Then
    (0,0): anon12_Then
Datatypes.dfy(356,7): Error: missing case in case statement: Nil
Execution trace:
    (0,0): anon0
    (0,0): anon10_Else
    (0,0): anon11_Then
    (0,0): anon12_Else
    (0,0): anon13_Then
Datatypes.dfy(82,19): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon20_Else
    (0,0): anon21_Then
    (0,0): anon4
    (0,0): anon22_Else
    (0,0): anon23_Then
    (0,0): anon24_Else
    (0,0): anon25_Then
Datatypes.dfy(170,15): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon4_Then
Datatypes.dfy(172,15): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon4_Else
    (0,0): anon5_Then
Datatypes.dfy(201,12): Error: destructor 'Car' can only be applied to datatype values constructed by 'XCons'
Execution trace:
    (0,0): anon0
Datatypes.dfy(204,16): Error: destructor 'Car' can only be applied to datatype values constructed by 'XCons'
Execution trace:
    (0,0): anon0
    (0,0): anon6_Then
Datatypes.dfy(225,16): Error: destructor 'c' can only be applied to datatype values constructed by 'T''
Execution trace:
    (0,0): anon0
    (0,0): anon5_Then

Dafny program verifier finished with 44 verified, 12 errors