Every kid at school knew about the Trenchcoat Mafia, but Columbine adults were unaware of its existence.
Everyone in Columbine both old and young was familiar with the Trenchcoat Mafia.
mnli hypothesis: Everyone in Columbine both old and young was familiar with the Trenchcoat Mafia. premise: Every kid at school knew about the Trenchcoat Mafia, but Columbine adults were unaware of its existence.