I have a business rule based on the equality of two collections.

The condition A=B doesn't do the job, for = is in this case an assignment operator.

So I tried to implement the condition with two conditions:

A->forAll(B->exists(A.nr=B.nr)) and

B->forAll(A->exists(B.nr=A.nr)), but nesting quantifiers doen't seem possible, the error message is 'mismatched brackets'.

Does anyone know how to solve this? Thanks.