U+21A0 RIGHTWARDS TWO HEADED ARROW

U+21A0 was added to Unicode in version 1.1 (1993). It belongs to the block Arrows in the Basic Multilingual Plane.

This character is a Math Symbol and is commonly used, that is, in no specific script. The character is also known as z notation total surjection and fast cursor right.

The glyph is not a composition. It has a Neutral East Asian Width. In bidirectional context it acts as Other Neutral and is not mirrored. In text U+21A0 behaves as Alphabetic regarding line breaks. It has type Other for sentence and Other for word breaks. The Grapheme Cluster Break is Any.

The Wikipedia has the following information about this codepoint:

In mathematics, a function f from a set X to a set Y is surjective (or onto), or a surjection, if every element y in Y has a corresponding element x in X such that f(x) = y. The function f may map more than one element of X to the same element of Y.

The term surjective and the related terms injective and bijective were introduced by Nicolas Bourbaki, the pseudonym for a group of mainly French 20th-century mathematicians who wrote a series of books presenting an exposition of modern advanced mathematics, beginning in 1935. The French prefix sur means over or above and relates to the fact that the image of the domain of a surjective function completely covers the function's codomain.

Representations

System Representation
8608
UTF-8 E2 86 A0
UTF-16 21 A0
UTF-32 00 00 21 A0
URL-Quoted %E2%86%A0
HTML-Escape ↠
Wrong windows-1252 Mojibake ↠
HTML-Escape ↠
HTML-Escape ↠
alias z notation total surjection
alias fast cursor right
LaTeX \twoheadrightarrow

Elsewhere

Complete Record

Property Value
Age (age) 1.1
Unicode Name (na) RIGHTWARDS TWO HEADED ARROW
Unicode 1 Name (na1) RIGHT TWO HEADED ARROW
Block (blk) Arrows
General Category (gc) Math Symbol
Script (sc) Common
Bidirectional Category (bc) Other Neutral
Combining Class (ccc) Not Reordered
Decomposition Type (dt) None
Decomposition Mapping (dm) ↠
Lowercase (Lower)
Simple Lowercase Mapping (slc) ↠
Lowercase Mapping (lc) ↠
Uppercase (Upper)
Simple Uppercase Mapping (suc) ↠
Uppercase Mapping (uc) ↠
Simple Titlecase Mapping (stc) ↠
Titlecase Mapping (tc) ↠
Case Folding (cf) ↠
ASCII Hex Digit (AHex)
Alphabetic (Alpha)
Bidi Control (Bidi_C)
Bidi Mirrored (Bidi_M)
Bidi Paired Bracket (bpb) ↠
Bidi Paired Bracket Type (bpt) None
Cased (Cased)
Composition Exclusion (CE)
Case Ignorable (CI)
Full Composition Exclusion (Comp_Ex)
Changes When Casefolded (CWCF)
Changes When Casemapped (CWCM)
Changes When NFKC Casefolded (CWKCF)
Changes When Lowercased (CWL)
Changes When Titlecased (CWT)
Changes When Uppercased (CWU)
Dash (Dash)
Deprecated (Dep)
Default Ignorable Code Point (DI)
Diacritic (Dia)
East Asian Width (ea) Neutral
Extender (Ext)
FC NFKC Closure (FC_NFKC) ↠
Grapheme Cluster Break (GCB) Any
Grapheme Base (Gr_Base)
Grapheme Extend (Gr_Ext)
Hex Digit (Hex)
Hangul Syllable Type (hst) Not Applicable
Hyphen (Hyphen)
ID Continue (IDC)
Ideographic (Ideo)
ID Start (IDS)
IDS Binary Operator (IDSB)
IDS Trinary Operator and (IDST)
InMC (InMC)
Indic Positional Category (InPC) NA
Indic Syllabic Category (InSC) Other
ISO 10646 Comment (isc)
Joining Group (jg) No_Joining_Group
Join Control (Join_C)
Jamo Short Name (JSN)
Joining Type (jt) Non Joining
Line Break (lb) Alphabetic
Logical Order Exception (LOE)
Math (Math)
Noncharacter Code Point (NChar)
NFC Quick Check (NFC_QC) Yes
NFD Quick Check (NFD_QC) Yes
NFKC Casefold (NFKC_CF) ↠
NFKC Quick Check (NFKC_QC) Yes
NFKD Quick Check (NFKD_QC) Yes
Numeric Type (nt) None
Numeric Value (nv) NaN
Other Alphabetic (OAlpha)
Other Default Ignorable Code Point (ODI)
Other Grapheme Extend (OGr_Ext)
Other ID Continue (OIDC)
Other ID Start (OIDS)
Other Lowercase (OLower)
Other Math (OMath)
Other Uppercase (OUpper)
Pattern Syntax (Pat_Syn)
Pattern White Space (Pat_WS)
Quotation Mark (QMark)
Radical (Radical)
Sentence Break (SB) Other
Simple Case Folding (scf) ↠
Script Extension (scx) Common
Soft Dotted (SD)
STerm (STerm)
Terminal Punctuation (Term)
Unified Ideograph (UIdeo)
Variation Selector (VS)
Word Break (WB) Other
White Space (WSpace)
XID Continue (XIDC)
XID Start (XIDS)
Expands On NFC (XO_NFC)
Expands On NFD (XO_NFD)
Expands On NFKC (XO_NFKC)
Expands On NFKD (XO_NFKD)