I think you might want to rephrase your question. The parent record can not give you a true/not true value for each record in a child table. It is, I assume, a one to many relationship. Perhaps I don't understand your question, but this is doubtful.
Ok let's use an example. An invoice record creates line item records for each item. How do I get a flag (true or false) if any of the amount fields are over 100.
From the context of Invoices:
Max ( LineItems::amount ) > 100