# Table of mathematical symbols by introduction date

The following table lists many specialized symbols commonly used in modern mathematics, ordered by their introduction date. The table can also be ordered alphabetically by clicking on the relevant header title.
| Symbol | Name | Date of earliest use | First author to use |
| — | horizontal bar for division | 14th century (approx.) | Nicole Oresme |
| + | plus sign | 1360 (approx.), abbreviation for Latin et resembling the plus sign | Nicole Oresme |
| − | minus sign | 1489 (first appearance of minus sign, and also first appearance of plus sign in print) | Johannes Widmann |
| √ | radical symbol (for square root) | 1525 (without the vinculum above the radicand) | Christoff Rudolff |
| (...) | parentheses (for precedence grouping) | 1544 (in handwritten notes) | Michael Stifel |
| (...) | parentheses (for precedence grouping) | 1556 | Niccolò Tartaglia |
| = | equals sign | 1557 | Robert Recorde |
| . | decimal separator | 1593 | Christopher Clavius |
| × | multiplication sign | 1618 | William Oughtred |
| ± | plus–minus sign | 1628 | William Oughtred |
| ∷ | proportion sign | 1628 | William Oughtred |
| $^n$√ | radical symbol (for nth root) | 1629 | Albert Girard |
| < > | strict inequality signs (less-than sign and greater-than sign) | 1631 | Thomas Harriot |
| x$^y$ | superscript notation (for exponentiation) | 1636 (using Roman numerals as superscripts) | James Hume |
| x$^y$ | superscript notation (for exponentiation) | 1637 (in the modern form) | René Descartes (La Géométrie) |
| x | Use of the letter x for an independent variable or unknown value. See History of algebra: The symbol x. | 1637 | René Descartes (La Géométrie) |
| √ ̅ | radical symbol (for square root) | 1637 (with the vinculum above the radicand) | René Descartes (La Géométrie) |
| % | percent sign | 1650 (approx.) | unknown |
| ∞ | infinity sign | 1655 | John Wallis |
| ÷ | division sign (a repurposed obelus variant) | 1659 | Johann Rahn |
| ≤ ≥ | unstrict inequality signs (less-than or equals to sign and greater-than or equals to sign) | 1670 (with the horizontal bar over the inequality sign, rather than below it) | John Wallis |
| ≤ ≥ | unstrict inequality signs (less-than or equals to sign and greater-than or equals to sign) | 1734 (with double horizontal bar below the inequality sign) | Pierre Bouguer |
| d | differential sign | 1675 | Gottfried Leibniz |
| ∫ | integral sign | 1675 | Gottfried Leibniz |
| : | colon (for division) | 1684 (deriving from use of colon to denote fractions, dating back to 1633) | Gottfried Leibniz |
| · | middle dot (for multiplication) | 1698 (perhaps deriving from a much earlier use of middle dot to separate juxtaposed numbers) | Gottfried Leibniz |
| ⁄ | division slash (a.k.a. solidus) | 1718 (deriving from horizontal fraction bar, invented by Abu Bakr al-Hassar in the 12th century) | Thomas Twining |
| ≠ | inequality sign (not equal to) | unknown | Leonhard Euler |
| x′ | prime symbol (for derivative) | 1748 | Leonhard Euler |
| Σ | summation symbol | 1755 | Leonhard Euler |
| ∝ | proportionality sign | 1768 | William Emerson |
| ∂ | partial differential sign (a.k.a. curly d or Jacobi's delta) | 1770 | Marquis de Condorcet |
| ≡ | identity sign (for congruence relation) | 1801 (first appearance in print; used previously in personal writings of Gauss) | Carl Friedrich Gauss |
| [x] | integral part (a.k.a. floor) | 1808 | Carl Friedrich Gauss |
| ! | factorial | 1808 | Christian Kramp |
| Π | product symbol | 1812 | Carl Friedrich Gauss |
| ⊂ ⊃ | set inclusion signs (subset of, superset of) | 1817 | Joseph Gergonne |
| ⊂ ⊃ | set inclusion signs (subset of, superset of) | 1890 | Ernst Schröder |
| |...| | absolute value notation | 1841 | Karl Weierstrass |
| |...| | determinant of a matrix | 1841 | Arthur Cayley |
| ‖...‖ | matrix notation | 1843 | Arthur Cayley |
| ∇ | nabla symbol (for vector differential) | 1846 (previously used by Hamilton as a general-purpose operator sign) | William Rowan Hamilton |
| ∩ ∪ | intersection union | 1888 | Giuseppe Peano |
| ℵ | aleph symbol (for transfinite cardinal numbers) | 1893 | Georg Cantor |
| ∈ | membership sign (is an element of) | 1894 | Giuseppe Peano |
| O | Big O Notation | 1894 | Paul Bachmann |
| {...} | braces, a.k.a. curly brackets (for set notation) | 1895 | Georg Cantor |
| $\mathbb {N}$ | Blackboard bold capital N (for natural numbers set) | 1895 | Giuseppe Peano |
| $\mathbb {Q}$ | Blackboard bold capital Q (for rational numbers set) | 1895 | Giuseppe Peano |
| ∃ | existential quantifier (there exists) | 1897 | Giuseppe Peano |
| · | middle dot (for dot product) | 1902 | J. Willard Gibbs |
| × | multiplication sign (for cross product) | 1902 | J. Willard Gibbs |
| ∨ | logical disjunction (a.k.a. OR) | 1906 | Bertrand Russell |
| (...) | matrix notation | 1909 | Maxime Bôcher |
| [...] | matrix notation | 1909 | Gerhard Kowalewski |
| ∮ | contour integral sign | 1917 | Arnold Sommerfeld |
| $\mathbb {Z}$ | Blackboard bold capital Z (for integer numbers set) | 1930 | Edmund Landau |
| ∀ | universal quantifier (for all) | 1935 | Gerhard Gentzen |
| → | arrow (for function notation) | 1936 (to denote images of specific elements) | Øystein Ore |
| → | arrow (for function notation) | 1940 (in the present form of f: X → Y) | Witold Hurewicz |
| ∅ | empty set sign | 1939 | André Weil / Nicolas Bourbaki |
| $\mathbb {C}$ | Blackboard bold capital C (for complex numbers set) | 1939 | Nathan Jacobson |
| ∎ | end of proof sign (a.k.a. tombstone) | 1950 | Paul Halmos |
| ⌊x⌋ ⌈x⌉ | greatest integer ≤ x (a.k.a. floor) smallest integer ≥ x (a.k.a. ceiling) | 1962 | Kenneth E. Iverson |