User blog comment:P進大好きbot/Japanese Googologists and Japanese Contributors to Googology/@comment-30846880-20191018224514

The hydra notation of BMS was made by Bashicu. Have a look this. https://www.slideshare.net/mobile/BashicuHyudora/2-77942065 My one is a multi hydra notation. Have a look this: https://googology.wikia.org/wiki/User_blog:Koteitan/The_Hydra_Diagram_based_on_Upper-Branch-Ignoring_Model_for_understanding_BM4_structure