U+1D54F "𝕏" Mathematical Double-Struck Capital X Unicode Character

Unicode Version 17.0

𝕏

U+1D54F "𝕏" Mathematical Double-Struck Capital X is a typographic symbol belonging to the "Mathematical Alphanumeric Symbols" block, designed for use in mathematical notation to represent a special set or variable, most commonly associated with the real numbers ℝ or the complex numbers ℂ in contexts where a double-struck style indicates a particular abstract structure. Its visual appearance mimics a bold, blackboard bold capital X, achieved through a stylistic variant that distinguishes it from ordinary letters, enabling mathematicians and logicians to denote specific concepts like the set of irrational numbers or a characteristic function without ambiguity in formal proofs or equations. This character was encoded in Unicode version 3.1, released in 2001, to support the growing need for consistent digital representation of mathematical text across platforms and fonts, ensuring that such specialized symbols remain accessible in electronic documents and on the internet.

General Properties

Code Point U+1D54F
Version Added 3.1
Name Mathematical Double-Struck Capital X
Block Mathematical Alphanumeric Symbols
General Category Uppercase Letter
Canonical Combining Class Not Reordered
Bidirectional Class Left To Right
Decomposition Type Font
Decomposition Mapping "X" U+0058 Latin Capital Letter X

Encodings

HTML Decimal Encoding 𝕏
HTML Hex Encoding 𝕏
UTF-8 Encoding 0xF0 0x9D 0x95 0x8F
UTF-16 Encoding 0xD835 0xDD4F
UTF-32 Encoding 0x0001D54F
C/C++/Java Escape \ud835\udd4f

Unicode Properties

NFC Quick Check Yes
NFD Quick Check Yes
Numeric Type None
Numeric Value NaN
Line Break Alphabetic
Uppercase Yes
Cased Yes
Changes When NFKC Casefolded Yes
NFKC Casefold "x" U+0078 Latin Small Letter X
NFKC Simple Casefold "x" U+0078 Latin Small Letter X
Script Common
Script Extensions Common
Indic Syllabic Category Other
ID Start Yes
XID Start Yes
ID Continue Yes
XID Continue Yes
Alphabetic Yes
Math Yes
Other Math Yes
Vertical Orientation Rotated
Grapheme Base Yes
Grapheme Cluster Break Other
Word Break Alphabetic letter
Sentence Break Upper