TraitUsingParentMembers.dfy(10,7): Error: assignment may update an array element not in the enclosing context's modifies clause
Execution trace:
    (0,0): anon0
    (0,0): anon5_Then
    (0,0): anon2
    (0,0): anon6_Then

Dafny program verifier finished with 7 verified, 1 error