U+1D557 "𝕗" Mathematical Double-Struck Small F Unicode Character

Unicode Version 17.0

𝕗

U+1D557 "𝕗" Mathematical Double-Struck Small F is a typographic symbol from the Mathematical Alphanumeric Symbols block, designed to represent the lowercase letter "f" in a double-struck or blackboard bold style, which is commonly used in mathematical notation to denote specific number sets, functions, or variables, such as the function f mapping from one domain to another. It is distinct from the standard Latin small letter f, as its heavy, outlined appearance helps avoid confusion with other symbols and aligns with the visual conventions of mathematical typesetting. This character is often employed in academic and technical writing, particularly in fields like algebra, analysis, and set theory, where precise, unambiguous notation is essential.

General Properties

Code Point U+1D557
Version Added 3.1
Name Mathematical Double-Struck Small F
Block Mathematical Alphanumeric Symbols
General Category Lowercase Letter
Canonical Combining Class Not Reordered
Bidirectional Class Left To Right
Decomposition Type Font
Decomposition Mapping "f" U+0066 Latin Small Letter F

Encodings

HTML Decimal Encoding 𝕗
HTML Hex Encoding 𝕗
UTF-8 Encoding 0xF0 0x9D 0x95 0x97
UTF-16 Encoding 0xD835 0xDD57
UTF-32 Encoding 0x0001D557
C/C++/Java Escape \ud835\udd57

Unicode Properties

NFC Quick Check Yes
NFD Quick Check Yes
Numeric Type None
Numeric Value NaN
Line Break Alphabetic
Lowercase Yes
Cased Yes
Changes When NFKC Casefolded Yes
NFKC Casefold "f" U+0066 Latin Small Letter F
NFKC Simple Casefold "f" U+0066 Latin Small Letter F
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 Lower