Backticks.dfy(38,4): Error: insufficient reads clause to invoke function
Execution trace:
    (0,0): anon0
    (0,0): anon7_Else
    (0,0): anon8_Else
    (0,0): anon6
Backticks.dfy(77,7): 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