The GAO as an institution, and the Comptroller General as an officer of the legislative branch, assist the Congress in exercising its responsibilities under the Constitution to oversee, investigate, and legislate.
The GAO is essential to Congress, who couldn't operate without it.
mnli hypothesis: The GAO is essential to Congress, who couldn't operate without it. premise: The GAO as an institution, and the Comptroller General as an officer of the legislative branch, assist the Congress in exercising its responsibilities under the Constitution to oversee, investigate, and legislate.