Arrow 63

Unicode
U+21CE
Category
Arrows
HTML Entity
⇎
CSS
\21CE
The ⇎ (left right double arrow with stroke) symbol represents logical non-equivalence in mathematics and formal logic. It acts as the negated version of the standard "if and only if" (⇔) arrow, indicating that two statements do not imply each other. While primarily found in academic papers and discrete math equations, you might also see it used in technical discussions to emphasize that two concepts are fundamentally different.

How to Type

Windows
Type 21CE then press Alt + X in Word, or press Win + . to open the symbol menu
macOS
Press Control + Command + Space, then search for 'left right double arrow with stroke'
Linux
Press Ctrl + Shift + U, type 21ce, and press Enter
HTML
⇎ or ⇎

In Programming

In formal logic and discrete mathematics formulas, ⇎ is used to explicitly state that two propositions, states, or variables are not logically equivalent.

Tags

arrow discrete math symbol double formal logic arrow iff negation left right left right double arrow with stroke logical non-equivalence negated negated biconditional not not equivalent not iff unicode negation symbol

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