Datatypes.dfy(297,10): Error BP5003: A postcondition might not hold on this return path.
Datatypes.dfy(295,15): 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(298,12): 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(349,5): Error: missing case in case statement: Cons
Execution trace:
    (0,0): anon0
    (0,0): anon7_Else
    (0,0): anon8_Then
Datatypes.dfy(349,5): 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(356,8): 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(356,8): 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(82,20): 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(170,16): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon4_Then
Datatypes.dfy(172,16): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon4_Else
    (0,0): anon5_Then
Datatypes.dfy(201,13): Error: destructor 'Car' can only be applied to datatype values constructed by 'XCons'
Execution trace:
    (0,0): anon0
Datatypes.dfy(204,17): Error: destructor 'Car' can only be applied to datatype values constructed by 'XCons'
Execution trace:
    (0,0): anon0
    (0,0): anon6_Then
Datatypes.dfy(225,17): 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