NestedMatch.dfy(173,14): Error: the calculation step between the previous line and this line might not hold
Execution trace:
    (0,0): anon0
    (0,0): anon142_Then
    (0,0): anon143_Else
    (0,0): anon144_Then
    (0,0): anon94
    (0,0): anon145_Then
    (0,0): anon96

Dafny program verifier finished with 12 verified, 1 error
