The ⊢ Symbol (Right Tack / Turnstile): Meaning, History, and How to Type It

The ⊢ symbol, known in Unicode as the Right Tack and widely referred to as the "turnstile," is a mathematical and logical operator used to denote a logical consequence. In formal logic, it represents syntactic consequence, meaning that a specific statement can be proven from a given set of assumptions using a defined set of rules. To mathematicians, logicians, and computer scientists, reading the expression "P ⊢ Q" simply translates to "Q is provable from P."

German mathematician Gottlob Frege first introduced this iconic symbol in his 1879 foundational logic book, *Begriffsschrift*. He created it by combining a vertical "judgment stroke" (asserting that a statement is true) with a horizontal "content stroke" (the statement itself). Over the past century, this clever typographic combination became the universal standard for indicating formal mathematical proofs and logical deductions.

In the Unicode Standard, the ⊢ symbol is officially named RIGHT TACK. It is located at code point U+22A2 within the Mathematical Operators block, a section dedicated to characters used in scientific, technical, and mathematical notation.

While you will mostly spot the turnstile in logic textbooks, computer science research, and type theory diagrams, it occasionally sneaks its way into everyday digital culture. Because of its clean, geometric shape, internet users sometimes repurpose the ⊢ symbol in text-based ASCII art and Japanese kaomoji. In these casual online contexts, it often visually represents a tiny hammer, a physical barrier, or a pushing motion, completely leaving behind its heavy academic baggage.

Typing the ⊢ symbol requires a few quick shortcuts since it does not appear on standard keyboards. On a Windows machine, you can type 22A2 followed by Alt + X in Microsoft Word, or hold the Alt key and type 8866 on your numeric keypad. Mac users can enable the Unicode Hex Input keyboard and press Option + 22A2. For web developers, the HTML entity ⊢ will render the symbol perfectly. If you are formatting a math document using LaTeX, just type \vdash.

The Right Tack is part of a larger family of logical symbols. It is most frequently compared to the Double Turnstile (⊨), which signifies that a statement is logically true in a specific model, rather than just mechanically provable. You might also run into its mirrored counterpart, the Left Tack (⊣), or the Up Tack (⊥) and Down Tack (⊤), which developers and mathematicians often use to represent "false" and "true" in boolean logic.