Complex sentence: The London NFL franchise is a hypothetical National Football League (NFL) American football team based in London, England; formed as a new expansion team, or by relocating one of the existing 32 NFL teams currently based in the United States.
Split into simpler sentences: The London NFL franchise is a potential American football team to be based in London, England. It would be a member of the National Football League (NFL), which currently consists of 32 teams based in the United States.