Question: The writings reevaluated as a "proto-Daoist" text is how many characters long? 
Sentence (from "Neiye"): For instance, it had the first references to cultivating the life forces "jing" "essence", "qi" "vital energy", and "shen" "spirit", which later became a fundamental concept in Daoist "Neidan" "internal alchemy", as well as the Three Treasures in traditional Chinese medicine.
Relevant evidence: No