The Mashantucket Pequots tribe is appealing last month’s ruling by the regional National Labor Relations Board that gives workers at the tribe’s Foxwoods Resort Casino an opportunity to unionize. About 3,000 Foxwoods dealers are set to vote on whether they will be represented by the United Auto Workers in late November. In the appeal, the Mashantuckets argue that tribal law prevails on the reservation in contrast to the labor board’s ruling.