U+27F8 "⟸" Long Leftwards Double Arrow Unicode Character

U+27F8 "⟸" Long Leftwards Double Arrow is a mathematical symbol that represents a double line arrow pointing to the left, typically used in formal logic, set theory, and linear algebra to denote biconditional relationships, logical equivalence, or a reverse mapping between sets. It is part of the Supplemental Arrows-A block and is distinct from its more common single-line counterpart by its thicker, double-stroked design, which often indicates a stronger or bidirectional implication when combined with its rightward counterpart. In many technical contexts, this character serves as a visual placeholder for the phrase "if and only if," though it lacks a universally standardized semantic meaning across all disciplines.

General Properties

Code Point	U+27F8
Version Added	3.2
Name	Long Leftwards Double Arrow
Block	Supplemental Arrows-A
General Category	Math Symbol
Canonical Combining Class	Not Reordered
Bidirectional Class	Other Neutral

Encodings

HTML Decimal Encoding	⟸
HTML Hex Encoding	⟸
UTF-8 Encoding	0xE2 0x9F 0xB8
UTF-16 Encoding	0x27F8
UTF-32 Encoding	0x000027F8
C/C++/Java Escape	\u27f8

Unicode Properties

NFC Quick Check	Yes
NFD Quick Check	Yes
NFKC Quick Check	Yes
NFKD Quick Check	Yes
Numeric Type	None
Numeric Value	NaN
Line Break	Alphabetic
Script	Common
Script Extensions	Common
Indic Syllabic Category	Other
Pattern Syntax	Yes
Math	Yes
Vertical Orientation	Rotated
Grapheme Base	Yes
Grapheme Cluster Break	Other
Word Break	Other
Sentence Break	Other