The two sides in the Caterpillar Inc. strike got together with a federal mediator in hopes of ending the five-month walkout. Negotiators for Caterpillar and the United Auto Workers union met in separate rooms, and three mediators shuttled between them. There was no word on what specifically was discussed or if any progress was made. The parties came together at the invitation of the Federal Mediation and Conciliation Service in the Chicago suburb of Hinsdale. The last talks were held March 26. The strike, launched Nov. 4, has idled almost 13,000 workers in Illinois.