premise: Keystone is an unincorporated community and census-designated place in central Keith County, Nebraska, United States. It lies along local roads near the North Platte River, northeast of the city of Ogallala, the county seat of Keith County. Its elevation is 3,100 feet (945 m). Although Keystone is unincorporated, it has a post office, with the ZIP code of 69144.
hypothesis: The elevation of Keystone is not more than 3,000 feet.
reason: The context mentions that Keystone's elevation is 3,100 feet. As such, it must be over 3,000 feet. The system could have been fooled by the use of a negative in the statement, or perhaps thought the elevation pertained to the city of Ogallala instead.