premise: In the southwestern United States is Phoenix, Arizona.
hypothesis: Phoenix ( [ ˈfiːnᵻks ] ) is the capital and most populous city of the U.S. state of Arizona . The Southwestern United States ( also known as the American Southwest ) is a region of the United States which includes Arizona , the western portion of New Mexico , bordered on the east by the Llano Estacado , southern Colorado and Utah below the 39th parallel , the `` horn '' of Texas below New Mexico , the southernmost triangle of Nevada , and the most southeastern portion of California , which encompasses the Mojave and Colorado Deserts . The population of the area is around 11 million people , with over half that in Arizona ; the most populous cities are Phoenix , El Paso , Las Vegas , Albuquerque , and Tucson .