≝
Math Operator 90
- Unicode
- U+225D
- Category
- Math
- HTML Entity
- ≝
- CSS
- \225D
The "Equal To By Definition" symbol (≝) features a standard equals sign with the abbreviation "def" resting above it. Mathematicians and logicians use this specific notation to declare that a new variable, function, or expression is defined by the value on the other side of the equation. While rarely seen in casual texting, it is a staple in academic papers, technical documentation, and complex proofs where establishing foundational definitions is crucial.
How to Type
- Windows
- Alt+8797
- macOS
- Control+Command+Space then search "equal to by definition"
- Linux
- Ctrl+Shift+U then 225D and Space
- HTML
- &eqdef; or ≝
In Programming
While rarely used directly in source code (where standard assignment operators like `=` or `:=` are preferred), this symbol frequently appears in rendered LaTeX documents, mathematical software, and technical comments to clearly distinguish a structural definition from a boolean equality check.
Tags
academic math symbol
def equals
defined by
definition
definitional equality
equal by definition
equals def
foundational definition
logic notation
mathematics
notation
relation
unicode definition symbol