The ≢ (Not Identical To) Symbol: Meaning, Usage, and How to Type It

The ≢ symbol, officially known as the "Not Identical To" symbol, is a mathematical operator used to indicate that two values, equations, or expressions are not exactly the same. Visually represented by three horizontal lines crossed out by a single forward slash, it stands in direct opposition to the ≡ (Identical To) symbol.

This character sits within the Mathematical Operators Unicode block and is assigned the code point U+2262. Its origin traces back to formal mathematics and logic, where precise distinctions between "equal" and "identical" are necessary. While a standard equal sign shows two things have the same numeric value, an identity symbol means they are exactly the same in all contexts and domains. Adding a diagonal slash to a math symbol traditionally negates its meaning, giving us the ≢ symbol to represent a lack of strict identity.

In mathematics and formal logic, ≢ is heavily used in modular arithmetic and congruence relations. It shows that two integers do not leave the same remainder when divided by a specific number. In programming and computer science, while the visual ≢ character isn't typically typed in source code due to standard keyboard limitations, the concept lives on as the strict inequality operator—often written as `!==` in languages like JavaScript or PHP. You might also spot the physical character in academic typography, digital notes, or scientific documentation where precise notation is required.

Typing the ≢ symbol depends on your operating system and software. On macOS, you can bring up the Character Viewer by pressing Control + Command + Space and searching for "not identical to". On Windows, you can type the Unicode value 2262 followed by Alt + X in applications like Microsoft Word. For web developers, the HTML entity is `≢` or `≢`. Of course, copying and pasting directly from a symbol library like EmojiAtlas is often the quickest method for everyday users.

Be careful not to confuse ≢ with the standard Not Equal To symbol (≠). While ≠ simply means two values are mathematically different (like 2 ≠ 3), ≢ implies a failure of strict identity or congruence. Other closely related symbols include the base Identical To symbol (≡) and the Almost Equal To symbol (≈), which is used for approximations rather than exact matches.