List of logic symbols

In logic, a set of symbols is commonly used to express logical representation. The following table lists many common symbols, together with their name, how they should be read out loud, and the related field of mathematics. Additionally, the subsequent columns contains an informal explanation, a short example, the Unicode location, the name for use in HTML documents, and the LaTeX symbol.

Basic logic symbols

Advanced or rarely used logical symbols

The following symbols are either advanced and context-sensitive or very rarely used:

Symbol	Unicode value	HTML value	HTML entity	LaTeX symbol	Logic Name	Read as	Category	Explanation
⥽	U+297D			\strictif	right fish tail			Sometimes used for “relation”, also used for denoting various ad hoc relations. The fish tail is also used as strict implication by C.I.Lewis ⥽.
̅	U+0305				combining overline			Used format for denoting Gödel numbers. Using HTML style “4̅” is an abbreviation for the standard numeral “SSSS0”. It may also denote a negation.
⌜ ⌝	U+231C U+231D			\ulcorner \urcorner	top left corner top right corner			Corner quotes, also called “Quine quotes”; for quasi-quotation, i.e. quoting specific context of unspecified expressions; also used for denoting Gödel number; for example “⌜G⌝” denotes the Gödel number of G., they are not symmetrical in some fonts. In some fonts they are only symmetrical in certain sizes. Alternatively the quotes can be rendered as ⌈ and ⌉
∄	U+2204			\nexists	there does not exist			Strike out existential quantifier. “¬∃” used some times instead.
⊙	U+2299			\odot	circled dot operator			A sign for the XNOR operator.
⟛	U+27DB				left and right tack			“Proves and is proved by”.
⊩	U+22A9				forces			One of this symbol’s uses is to mean “truthmakes” in the truthmaker theory of truth. It is also used to mean “forces” in the set theory method of forcing.
⟡	U+27E1				white concave-sided diamond	never	modal operator
⟢	U+27E2				white concave-sided diamond with leftwards tick	was never	modal operator
⟣	U+27E3				white concave-sided diamond with rightwards tick	will never be	modal operator
⟤	U+25A4				white square with leftwards tick	was always	modal operator
⟥	U+25A5				white square with rightwards tick	will always be	modal operator
⋆	U+22C6				star operator			May sometimes be used for ad-hoc operators.
⌐	U+2310				reversed not sign
⨇	U+2A07				two logical AND operator