⇐ Left Double Arrow Symbol: Meaning, Math & How to Type
The ⇐ (Left Double Arrow) is a typographical symbol primarily used in mathematics and formal logic to denote implication or backwards assignment. Visually distinct from a standard single arrow, it features a double-lined shaft pointing to the left. In digital text, it often signals a return, an "implied by" relationship, or an emphatic visual cue directing attention to previous information.
In the Unicode standard, this symbol is officially named LEFTWARDS DOUBLE ARROW. It occupies the code point U+21D0 and resides within the "Arrows" block, a comprehensive section dedicated to directional lines and pointers used across various digital platforms.
You will mostly find the ⇐ symbol in mathematics and formal logic, where it represents the "is implied by" relation. If a mathematician writes "A ⇐ B", it means statement A is true if statement B is true. In programming and computer science, developers sometimes use it in pseudocode to indicate variable assignment or a return value. Outside of academia, the left double arrow serves as a strong typographical pointer. On social media and messaging apps, users type it to draw immediate attention to text on the left, point back to a previous message, or build decorative borders and text-based emoticons (kaomoji).
Typing the ⇐ symbol depends on your operating system and software. On Windows, you can insert it in Microsoft Word by typing 21D0 followed by Alt + X. Alternatively, hold the Alt key and type 8656 on the numeric keypad. Mac users can pull it up easily using the Character Viewer by pressing Cmd + Ctrl + Space and searching for "Leftwards Double Arrow". Web developers and bloggers can render it flawlessly in HTML by using the named entity ⇐ or the decimal code ⇐.
The left double arrow sits within a larger family of directional markers. It contrasts with the standard single left arrow (←), which simply indicates physical direction rather than mathematical implication. Its direct counterpart is the right double arrow (⇒), which means "implies" in logical statements. Finally, the left-right double arrow (⇔) combines both symbols to represent "if and only if" or strict logical equivalence.