Char.dfy(48,20): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon9_Then
    (0,0): anon10_Then
Char.dfy(52,20): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon9_Then
    (0,0): anon11_Else
Char.dfy(63,16): Error: assertion violation
Execution trace:
    (0,0): anon0
    (0,0): anon5_Else

Dafny program verifier finished with 8 verified, 3 errors