This revised edition of the classic Thirteen Chapters with notes and index was prepared for teachers, scholars, and serious students seeking both T’’ai-chi treasures and a broader understanding of the sources of Cheng’’s teaching. In the Preface he states: "My teacher, Yang Ch’’eng-fu, suspended the family transmission. He did not lightly share his knowledge, fearing it would fall into the wrong hands. Therefore I have taken all of these secrets and presented them here in this book." 101 pages