This isn't really a recursion problem. Recursion means that X uses X, for example when the column evaluator must use the column evaluator to get a value.
What you describe is a case where the logical expression includes "A and not A", which as written is a
contradiction. Your searches aren't so clear because the left-hand side includes other conditions not related to A, but it still could end up in the same place.
The answer: don't do that. You have found one way -- construct a search that doesn't use the same subsearch more than once. Another way that might work is to use restrictions, available in the virtual library tab, because they are fully evaluated before sub-searches are done.