U+21CB "⇋" Leftwards Harpoon over Rightwards Harpoon Unicode Character
Unicode Version 17.0
⇋
U+21CB "⇋" Leftwards Harpoon over Rightwards Harpoon is a mathematical symbol used primarily in chemical notation and vector analysis to represent a reversible equilibrium or a two-way exchange between two entities. In chemistry, it often denotes a reaction that occurs simultaneously in both forward and backward directions, distinct from the double-headed arrow that indicates resonance. The symbol combines an upper left-pointing harpoon and a lower right-pointing harpoon stacked vertically, conveying the concept of mutual or bidirectional interaction. It can also appear in logic or physics contexts to signify a reciprocal relationship or a bidirectional mapping between elements.
General Properties
| Code Point | U+21CB |
| Version Added | 1.1 |
| Name | Leftwards Harpoon over Rightwards Harpoon |
| Unicode 1.0 Name | Left Harpoon over Right Harpoon |
| Block | Arrows |
| General Category | Other Symbol |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Other Neutral |
Encodings
| HTML Decimal Encoding | ⇋ |
| HTML Hex Encoding | ⇋ |
| UTF-8 Encoding | 0xE2 0x87 0x8B |
| UTF-16 Encoding | 0x21CB |
| UTF-32 Encoding | 0x000021CB |
| C/C++/Java Escape | \u21cb |
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 |
| Other Math | Yes |
| Vertical Orientation | Rotated |
| Grapheme Base | Yes |
| Grapheme Cluster Break | Other |
| Word Break | Other |
| Sentence Break | Other |