Home: go to the homepage U+2100 to U+214F Letterlike Symbols

U+212DBlack-Letter Capital C

U+212D was added in Unicode version 1.1 in 1993. It belongs to the block U+2100 to U+214F Letterlike Symbols in the U+0000 to U+FFFF Basic Multilingual Plane.

This character is a Uppercase Letter and is commonly used, that is, in no specific script.

The glyph is a font version of the glyph Latin Capital Letter C. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. The word that U+212D forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with one other glyph.

In set theory, the cardinality of the continuum is the cardinality or "size" of the set of real numbers $R$, sometimes called the continuum. It is an infinite cardinal number and is denoted by $c$ (lowercase Fraktur "c") or $|R|$.

The real numbers $R$ are more numerous than the natural numbers $N$. Moreover, $R$ has the same number of elements as the power set of $N.$ Symbolically, if the cardinality of $N$ is denoted as ${\aleph }_{0}$, the cardinality of the continuum is

This was proven by Georg Cantor in his uncountability proof of 1874, part of his groundbreaking study of different infinities. The inequality was later stated more simply in his diagonal argument in 1891. Cantor defined cardinality in terms of bijective functions: two sets have the same cardinality if, and only if, there exists a bijective function between them.

Between any two real numbers a < b, no matter how close they are to each other, there are always infinitely many other real numbers, and Cantor showed that they are as many as those contained in the whole set of real numbers. In other words, the open interval (a,b) is equinumerous with $R.$ This is also true for several other infinite sets, such as any n-dimensional Euclidean space ${R}^{n}$ (see space filling curve). That is,

The smallest infinite cardinal number is ${\aleph }_{0}$ (aleph-null). The second smallest is ${\aleph }_{1}$ (aleph-one). The continuum hypothesis, which asserts that there are no sets whose cardinality is strictly between ${\aleph }_{0}$ and $c$, means that $c={\aleph }_{1}$. The truth or falsity of this hypothesis is undecidable and cannot be proven within the widely used Zermelo–Fraenkel set theory with axiom of choice (ZFC).

Representations

System Representation
8493
UTF-16 21 2D
UTF-32 00 00 21 2D
HTML hex reference &#x212D;
Wrong windows-1252 Mojibake â„­
HTML named entity &Cayleys;
HTML named entity &Cfr;
LATEX \mathfrak{C}

Complete Record

Property Value
Age (age) 1.1 (1993)
Unicode Name (na) BLACK-LETTER CAPITAL C
Unicode 1 Name (na1) BLACK-LETTER C
Block (blk) Letterlike Symbols
General Category (gc) Uppercase Letter
Script (sc) Common
Bidirectional Category (bc) Left To Right
Combining Class (ccc) Not Reordered
Decomposition Type (dt) font
Decomposition Mapping (dm) Latin Capital Letter C
Lowercase (Lower)
Simple Lowercase Mapping (slc) Black-Letter Capital C
Lowercase Mapping (lc) Black-Letter Capital C
Uppercase (Upper)
Simple Uppercase Mapping (suc) Black-Letter Capital C
Uppercase Mapping (uc) Black-Letter Capital C
Simple Titlecase Mapping (stc) Black-Letter Capital C
Titlecase Mapping (tc) Black-Letter Capital C
Case Folding (cf) Black-Letter Capital C
ASCII Hex Digit (AHex)
Alphabetic (Alpha)
Bidi Control (Bidi_C)
Bidi Mirrored (Bidi_M)
Composition Exclusion (CE)
Case Ignorable (CI)
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)
Cased (Cased)
Full Composition Exclusion (Comp_Ex)
Default Ignorable Code Point (DI)
Dash (Dash)
Deprecated (Dep)
Diacritic (Dia)
Emoji Modifier Base (EBase)
Emoji Component (EComp)
Emoji Modifier (EMod)
Emoji Presentation (EPres)
Emoji (Emoji)
Extender (Ext)
Extended Pictographic (ExtPict)
FC NFKC Closure (FC_NFKC) Latin Small Letter C
Grapheme Cluster Break (GCB) Any
Grapheme Base (Gr_Base)
Grapheme Extend (Gr_Ext)
Hex Digit (Hex)
Hyphen (Hyphen)
ID Continue (IDC)
ID Start (IDS)
IDS Binary Operator (IDSB)
IDS Trinary Operator and (IDST)
IDSU (IDSU) 0
ID_Compat_Math_Continue (ID_Compat_Math_Continue) 0
ID_Compat_Math_Start (ID_Compat_Math_Start) 0
Ideographic (Ideo)
InCB (InCB) None
Indic Mantra Category (InMC)
Indic Positional Category (InPC) NA
Indic Syllabic Category (InSC) Other
Jamo Short Name (JSN)
Join Control (Join_C)
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) Latin Small Letter C
NFKC Quick Check (NFKC_QC) No
NFKC_SCF (NFKC_SCF) Latin Small Letter C
NFKD Quick Check (NFKD_QC) No
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)
Prepended Concatenation Mark (PCM)
Pattern Syntax (Pat_Syn)
Pattern White Space (Pat_WS)
Quotation Mark (QMark)
Regional Indicator (RI)
Sentence Break (SB) Upper
Soft Dotted (SD)
Sentence Terminal (STerm)
Terminal Punctuation (Term)
Unified Ideograph (UIdeo)
Variation Selector (VS)
Word Break (WB) Alphabetic Letter
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)
Bidi Paired Bracket (bpb) Black-Letter Capital C
Bidi Paired Bracket Type (bpt) None
East Asian Width (ea) neutral
Hangul Syllable Type (hst) Not Applicable
ISO 10646 Comment (isc)
Joining Group (jg) No_Joining_Group
Joining Type (jt) Non Joining
Line Break (lb) Alphabetic
Numeric Type (nt) none
Numeric Value (nv) not a number
Simple Case Folding (scf) Black-Letter Capital C
Script Extension (scx)
Vertical Orientation (vo) R