⟵ Long Left Arrow: Meaning, Usage, and How to Type It
The Long Left Arrow (⟵) is a typographical and mathematical Unicode symbol used to indicate a directional relationship, a reverse process, or an assignment. While it shares the same basic meaning as a standard left arrow, its elongated shaft provides extra visual emphasis. This extra length makes it highly sought after in complex mathematical equations, chemical formulas, and diagrams where horizontal spacing is critical for readability.
In the Unicode standard, the Long Left Arrow sits at code point U+27F5. You can find it housed within the Supplemental Arrows-A block, a section dedicated to expanding the variety of directional symbols available for specialized and technical writing.
This extended arrow does some heavy lifting across several disciplines. In mathematics and formal logic, ⟵ often represents a reverse implication or denotes that a value is being mapped. Chemists use it to illustrate reverse reactions in molecular diagrams. In computer science, particularly in pseudocode or languages like APL and R, left-facing arrows represent value assignment. While programmers typically type two characters (<-) on a standard keyboard, typesetting systems often render them into this single, sleek long arrow. On social media and in casual digital typography, creators use ⟵ to draw massive attention to a previous point, a quoted post, or a specific link on a webpage.
Typing the Long Left Arrow requires a bit of know-how, as it doesn't appear on standard keyboards. If you are writing in HTML, you can use the named entity ⟵ or the decimal code ⟵. Mac users can quickly access it by pressing Control + Command + Space to bring up the Character Viewer and searching for "long left arrow." Windows users can find it in the Character Map app or type 27F5 followed by Alt + X in applications like Microsoft Word. For math and science writers using LaTeX, the command \longleftarrow generates the symbol perfectly.
Understanding the Long Left Arrow also means knowing its graphical siblings. The standard Leftwards Arrow (←, U+2190) is its most direct relative, used for general, compact directional pointing. The Long Right Arrow (⟶, U+27F6) simply flips the direction, making it the go-to for forward chemical reactions and logical progression. Finally, the Long Left Right Arrow (⟷, U+27F7) combines both directions, representing a two-way street, logical equivalence, or reversible reactions.