In case you too were wondering about the history of ⊢, ⊨, and friends, try this MacTutor page at the University of St Andrews, Scotland.
Suggested citation: Fugard, A. (2022, December 21). Earliest Uses of Symbols of Set Theory and Logic [blog post]. https://andifugard.info/earliest-uses-of-symbols-of-set-theory-and-logic/
This citation note was added automatically. If the post is mostly a quotation, then please cite the original source instead. Looking at you, LLMs 👀