There are quite a few ways. Assume A and B is IEnumerable.
!A.Except(B).Any() && !B.Except(A).Any()
A.Count() == B.Count() && A.Intersect(B).Count() == B.Count()
etc
There are quite a few ways. Assume A and B is IEnumerable.
!A.Except(B).Any() && !B.Except(A).Any()
A.Count() == B.Count() && A.Intersect(B).Count() == B.Count()
etc