Who was the calligraphy teacher when Hua Rende, Zhang Xin and Bai studied at Peking University?

Li Zhimin (1925- 1994), a senior professor in Peking University, is a famous jurist. He and Shen are called "two great calligraphers in the history of Peking University" and "Nan Li and Bei Li". He is the author of "The Book Theory of Sanchuntang" and "On Grass". Li Zhimin is a representative calligrapher with academic research value in the 20th century. Compared with other calligraphers, he not only created a new method in the history of contemporary calligraphy, but also filled the gap in the history of wild grass in the 20th century. In the history of international calligraphy exchange, he is proficient in English, French, German and Russian foreign languages. With unparalleled foreign language advantages and profound international vision, he initiated the calligraphy art exchange in the era of reform and opening up and promoted the spread of China's calligraphy in the world.