Date Conflict formula

Hi! I’m looking to create a formula that returns “CONFLICT” if collaborators are trying to sign up for the same resources at the same time. I have a “Start Time” column, and “Finish Time” column as well as a “Resources” column. I’d like to find a formula that returns “CONFLICT” if people put overlapping time in AND the resources are the same. It feels like a “IS_SAME” formula nested within an “IF, THEN” formula, but for the life of me I can’t figure it out.