The **tee** (**⊤**, `\top`

in LaTeX) also called **down tack** (as opposed to the up tack) or **verum** is a symbol used to represent:

- The top element in lattice theory.
- The truth value of being true in logic, or a sentence (e.g., formula in propositional calculus) which is unconditionally true.
^{[1]}^{[2]}^{[3]}^{[4]}By definition, every tautology is logically equivalent to the verum. - The top type in type theory.
- Mixed radix encoding in the APL programming language.

A similar-looking superscript T may be used to mean the transpose of a matrix.^{[5]}

## Encoding

In Unicode, the tee character is encoded as U+22A4 ⊤ DOWN TACK (HTML `⊤`

**·** `⊤, ⊤`

).^{[6]} The symbol is encoded in LaTeX as `\top`

.

## See also

## Notes

**^**"Comprehensive List of Logic Symbols".*Math Vault*. 2020-04-06. Retrieved 2020-08-14.**^**"tautology | Definition & Facts".*Encyclopedia Britannica*. Retrieved 2020-08-14.**^**"Definition of TAUTOLOGY".*www.merriam-webster.com*. Retrieved 2020-08-14.**^**Weisstein, Eric W. "Tautology".*mathworld.wolfram.com*. Retrieved 2020-08-14.**^**"Compendium of Mathematical Symbols".*Math Vault*. 2020-03-01. Retrieved 2020-08-14.**^**"Mathematical Operators – Unicode" (PDF). Retrieved 2013-07-20.