Mahayana Buddhism and the Prajnaparamita Sutra
Transformation of the concept of the sky from Theravada Buddhism, Theravada Buddhism, and Sakyamuni Buddhism (Agon Sutra) to Mahayana Buddhism (Prajnaparamita Sutra), Zen Buddhism (Soto, Rinzai, Obaku) and Esoteric Buddhism (Tendai, Shingon)