0x21D0

0x21D0 is the hexadecimal notation for the Unicode code point U+21D0, which represents the LEFTWARDS DOUBLE ARROW character. The glyph for this code point is ⇐, and it resides in the Unicode Mathematical Operators block. It is used in mathematics and logic to denote implication or a relation that runs in the reverse direction, with the forward implication commonly shown by the related symbol U+21D2 (⇒).

In practice, 0x21D0 is encountered in authoring and rendering mathematical notation, formal grammars, and logical expressions. While ⇐ often conveys “is implied by” or a reverse conditional, the exact meaning can vary by domain and accompanying symbols. The more common forward implication is shown with ⇒, and the double-arrow family also includes symbols like ⇔ (U+21D4) for “if and only if,” which can help distinguish directional meaning in formal texts.

Encoding and representations: U+21D0 can be encoded in UTF-8 as the three-byte sequence E2 87 90. In UTF-16, it is represented as a single code unit 0x21D0 since it lies within the Basic Multilingual Plane. In HTML, it can be written as the named entity &LeftDoubleArrow; or numerically as ⇠. In LaTeX, the symbol is produced with \Leftarrow.

Related symbols include U+21D2 RIGHTWARDS DOUBLE ARROW (⇒) and U+21D4 LEFT RIGHT DOUBLE ARROW (⇔), which together cover common directional implications in formal notation.