Input (grade 12): Since 1980, the chert has been examined by the MÃ 1\/4 nster school, and from 1987 Aberdeen University, who confirmed that the chert was indeed produced by a hot spring setting.
Output (grade 6): Since 1980, the chert has been examined by the MÃ 1\/4 nster group, and from 1987 by Aberdeen University. They showed the chert was indeed produced by a hot spring setting.