Table of mathematical symbols by introduction date

The following table lists many specialized symbols commonly used in modern mathematics, ordered by their introduction date.

Symbol	Name	Date of earliest use	First author to use
—	horizontal bar for division	14th century	Nicole Oresme
+	plus sign	1360, abbreviation for Latin et resembling the plus sign	Nicole Oresme
−	minus sign	1489	Johannes Widmann
√	radical symbol	1525	Christoff Rudolff
	parentheses	1544	Michael Stifel
	parentheses	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	1629	Albert Girard
< >	strict inequality signs	1631	Thomas Harriot
x^y	superscript notation	1636	James Hume
x^y	superscript notation	1637	René Descartes
x	Use of the letter x for an independent variable or unknown value. See History of algebra: The symbol x.	1637	René Descartes
√ ̅	radical symbol	1637	René Descartes
%	percent sign	1650	unknown
∞	infinity sign	1655	John Wallis
÷	division sign	1659	Johann Rahn
≤ ≥	unstrict inequality signs	1670	John Wallis
≤ ≥	unstrict inequality signs	1734	Pierre Bouguer
d	differential sign	1675	Gottfried Leibniz
∫	integral sign	1675	Gottfried Leibniz
:	colon	1684	Gottfried Leibniz
·	middle dot	1698	Gottfried Leibniz
⁄	division slash	1718	Thomas Twining
≠	inequality sign	unknown	Leonhard Euler
x	prime symbol	1748	Leonhard Euler
Σ	summation symbol	1755	Leonhard Euler
∝	proportionality sign	1768	William Emerson
∂	partial differential sign	1770	Marquis de Condorcet
≡	identity sign	1801	Carl Friedrich Gauss
	integral part	1808	Carl Friedrich Gauss
!	factorial	1808	Christian Kramp
Π	product symbol	1812	Carl Friedrich Gauss
⊂ ⊃	set inclusion signs	1817	Joseph Gergonne
⊂ ⊃	set inclusion signs	1890	Ernst Schröder
\|...\|	absolute value notation	1841	Karl Weierstrass
\|...\|	determinant of a matrix	1841	Arthur Cayley
‖...‖	matrix notation	1843	Arthur Cayley
∇	nabla symbol	1846	William Rowan Hamilton
∩ ∪	intersection union	1888	Giuseppe Peano
ℵ	aleph symbol	1893	Georg Cantor
∈	membership sign	1894	Giuseppe Peano
O	Big O Notation	1894	Paul Bachmann
	braces, a.k.a. curly brackets	1895	Georg Cantor
	Blackboard bold capital N	1895	Giuseppe Peano
	Blackboard bold capital Q	1895	Giuseppe Peano
∃	existential quantifier	1897	Giuseppe Peano
·	middle dot	1902	J. Willard Gibbs
×	multiplication sign	1902	J. Willard Gibbs
∨	logical disjunction	1906	Bertrand Russell
	matrix notation	1909	Maxime Bôcher
	matrix notation	1909	Gerhard Kowalewski
∮	contour integral sign	1917	Arnold Sommerfeld
	Blackboard bold capital Z	1930	Edmund Landau
∀	universal quantifier	1935	Gerhard Gentzen
→	arrow	1936	Øystein Ore
→	arrow	1940	Witold Hurewicz
∅	empty set sign	1939	André Weil / Nicolas Bourbaki
	Blackboard bold capital C	1939	Nathan Jacobson
∎	end of proof sign	1950	Paul Halmos
⌊x⌋ ⌈x⌉	greatest integer ≤x smallest integer ≥x	1962	Kenneth E. Iverson