Rightwards Double Arrow with Stroke ⇏

The Rightwards 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+21CF in the Universal Character Set.

The rightwards double arrow with stroke negates the logical implication symbol. It indicates that 'A does not imply B' in formal logic. This is a critical symbol in mathematical logic for distinguishing valid from invalid implications and in constructing counterexample arguments.

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 Rightwards 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 rightwards double arrow in formal logic to state 'does not imply' (A ⇏ B). It is essential for mathematical proofs, philosophical logic, and computer science formal methods where the distinction between implication and non-implication must be precisely expressed.