We want to create a validation rule for Unlimited opening while creating requisition

Summary: We have a requirement where we want to create a validation rule which gives error when an unlimited opening flag is true while creating requisition. I have created a SR for this and was asked to raise this on CC to get confirmation from product team. If anyone else here has created such rules can you please share if that was possible or advice how can we build this rule

Content (please ensure you mask any confidential information): We tried to create validation rule below is the screenshot but it is letting us continue and not giving us any error