Verify the textual reality and geopolitical adoption of the 'Basic Structure Doctrine' across varying legal systems:
1. The terminology and framework of the doctrine are explicitly codified and defined within the primary text of the Indian Constitution.
2. The Republic of Singapore operates as the only international sovereign state outside of India to formally acknowledge and apply the doctrine.
3. The Republic of Bangladesh officially recognizes the doctrine and has explicitly incorporated it into the written text of its national constitution.