Leftwards Double Arrow with Stroke ⇍

The Leftwards Double Arrow with Stroke character (⇍) is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference ⇍, the decimal numeric character reference ⇍, or the hexadecimal numeric reference ⇍. The character is assigned Unicode code point U+21CD in the Universal Character Set.

The leftwards double arrow with stroke is a double-line left arrow crossed by a diagonal, negating the logical implication. In formal logic, it indicates that the reverse implication does not hold — that A does not imply B (when read right to left).

Arrow entities serve as directional indicators in navigation interfaces, mathematical expressions, flowcharts, and textual content throughout the web. Because they render as scalable text characters rather than bitmap images, HTML arrow entities are resolution-independent, styleable with CSS properties like color and font-size, and fully accessible to assistive technologies including screen readers.

When deciding how to encode the Leftwards Double Arrow with Stroke character in your HTML documents, the named entity ⇍ is generally the most readable choice for developers reviewing or maintaining source code. The decimal form ⇍ and hexadecimal form ⇍ are equally valid alternatives that work in contexts where named entities may not be supported, or when generating HTML output programmatically from server-side code. All three representations produce identical visual output in every modern web browser.

Use the negated leftwards double arrow in formal logic and mathematical proofs to indicate that a reverse implication does not hold. It is the negation of ⇐ and is important in logical argumentation where distinguishing between valid and invalid implications is essential.