The federal government has always considered frequent flyer awards to be property of the government, and sought to reduce travel costs by requiring their use only for official travel.
Frequent flyer miles are not used by the federal government. 
mnli hypothesis: Frequent flyer miles are not used by the federal government.  premise: The federal government has always considered frequent flyer awards to be property of the government, and sought to reduce travel costs by requiring their use only for official travel.