If 
and 
are equal by definition (i.e., 
is defined as 
), then this is written symbolically as 
, 
,
or sometimes 
.
Defined
See also
Colon, Equal, EquivalentExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Defined." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Defined.html