The city of Chicago could not withhold an entire document from a Freedom of Information Act request because it contained some protected facts, an appeals panel held.“Having determined that the requested [p]lan is likely a mix of both exempt and nonexempt information, we conclude that the circuit court erred in grant summary judgment for the [c]ity,” Justice Cynthia Y. Cobbs wrote in a 10-page opinion filed Tuesday. “Our supreme court has explained that “the mere ‘commingling’ of exempt …