Glen Arbor residents might recognize John Farah. The dentist from Ann Arbor owns a condominium at the Homestead Resort and likes to jog a 15-mile route around Big Glen Lake during his summer visits up north. On Monday in Boston, Farah was maintaining a solid pace, despite nagging small injuries that had interrupted his training cycle of late. He was hoping to finish the marathon at 4 hours and 15 minutes, and then greet his wife Jackie and her daughter Erin at the finish line. The plan was to take a train to Erin’s apartment so Farah could shower and change, and then head to Logan Airport for a flight back to Detroit.