Backticks.dfy(38,5): Error: insufficient reads clause to invoke function
Execution trace:
    (0,0): anon0
    (0,0): anon5_Else
    (0,0): anon6_Else
Backticks.dfy(77,8): Error: call may violate context's modifies clause
Execution trace:
    (0,0): anon0
    (0,0): anon3_Then

Dafny program verifier finished with 13 verified, 2 errors