The ≁ Symbol (Not Tilde): Meaning, Math Usage, and How to Type It
The ≁ symbol, officially known in Unicode as "Not Tilde," is a mathematical operator used to indicate that two values or expressions are not similar or not asymptotically equal. Visually, it consists of a standard tilde (~) intersected by a diagonal slash, which acts as a universal sign of negation in mathematics. Whenever you need to express that a proportional or geometric relationship does not exist, this is the symbol you reach for.
In the Unicode standard, ≁ sits at code point U+2241 within the Mathematical Operators block. This block is home to a massive collection of characters designed for academic, scientific, and technical writing. The "Not Tilde" symbol functions as the direct opposite of the standard tilde (~), which often denotes similarity in geometry or an "order of magnitude" approximation in physics.
You will primarily encounter the ≁ symbol in advanced mathematics and science. In geometry, if two triangles share different angles and proportions, you might write Triangle A ≁ Triangle B to show they are not similar. In calculus and mathematical analysis, it shows that two functions do not grow at the same rate. While rarely used in everyday social media or casual messaging, a clever internet user might drop it in a text to say two things are "definitely not similar" or "vibes don't match," though you might have to explain the joke. In programming, developers typically rely on keyboard-friendly combinations like `!=` or `!~` for negation, reserving ≁ for specialized document formatting systems like LaTeX.
Typing the ≁ symbol requires a few shortcuts, as it doesn't have a dedicated key on standard keyboards. On Windows, you can type 2241 followed by Alt + X in Microsoft Word, or use the numeric keypad by holding Alt and typing 8769. Mac users can switch their keyboard to Unicode Hex Input and hold the Option key while typing 2241. If you are coding in HTML, you can insert it using `≁` or `≁`. For those using LaTeX to write mathematical papers, the command `\nsim` generates this exact character.
Several other mathematical symbols share a visual or conceptual relationship with ≁. The most obvious is the standard Tilde (~), which indicates the similarity that the slash negates. The Not Equal To symbol (≠) is a more common cousin, used for direct numerical inequality rather than proportional differences. Additionally, the Not Almost Equal To symbol (≉) negates a double tilde, specifically rejecting the idea that two values are close approximations of one another.