concurrent-frame-empty.dfy(6,23): Error: reads clause could not be proved to be empty ({:concurrent} restriction)
 Asserted expression: forall c: C<T> :: ReadsEmpty.reads(c) == {}
concurrent-frame-empty.dfy(12,21): Error: modifies clause could not be proved to be empty ({:concurrent} restriction)
 Asserted expression: forall c: C<T> :: ModifiesEmpty.modifies(c) == {}

Dafny program verifier finished with 0 verified, 2 errors
