• Normally, entries of a glossary are structured by topics and sorted alphabetically. This is not possible here, as there is no natural order on symbols, and many symbols … See more

=    (equals sign) 1. Denotes equality. 2. Used for naming a mathematical object in a sentence like "let $${\displaystyle x=E}$$", … See more

∅ Denotes the empty set, and is more often written $${\displaystyle \emptyset }$$. Using set-builder notation, it may also be denoted $${\displaystyle \{\}}$$. #    (number sign) 1. … See more

The blackboard bold typeface is widely used for denoting the basic number systems. These systems are often also denoted by the … See more

+    (plus sign) 1. Denotes addition and is read as plus; for example, 3 + 2. 2. Denotes that a number is positive and is read as plus. Redundant, but sometimes used for emphasizing that a number is positive, specially when other numbers in the context are or … See more

<    (less-than sign) 1. Strict inequality between two numbers; means and is read as "less than". 2. Commonly used for denoting any strict order. 3. Between two groups, may mean … See more

Several logical symbols are widely used in all mathematics, and are listed here. For symbols that are used only in mathematical logic, or are rarely used, see List of logic symbols.
¬    (not sign) Denotes logical negation, and is read as "not". If E … See more