A mathematical symbol is a figure or a combination of figures that is used to represent a mathematical object, an action on … 展开

• 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 are used in different parts of mathematics wit… 展开

+    (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, speciall… 展开

=    (equals sign) 1. Denotes equality. 2. Used for naming a mathematical object in a sentence like "let  ", where E is an expression. See also ≝, ≜ or . Any of these is sometimes used for naming a mathematical obj… 展开

<    (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 that the first one is a proper subgrou… 展开

∅ Denotes the empty set, and is more often written . Using set-builder notation, it may also be denoted . #    (number sign) 1. Number of elements: may denote the cardinality of the set S. An alternative notation is ; … 展开