\xlongequal{abc}The command \xlongequal{abc} is used to create an extensible equal sign with a label 'abc' above it. This is particularly useful in mathematical expressions where you want to denote equivalence or equality with additional context or explanation provided by the label.
Indicating that the sum of a and b is equal to c, with 'abc' providing additional context or explanation.
a + b \xlongequal{abc} cShowing that two functions f(x) and g(x) are equivalent, with 'abc' as a label for further clarification.
f(x) \xlongequal{abc} g(x)Demonstrating that the integral of x squared from 0 to 1 equals one-third, with 'abc' offering extra information or context.
\int_0^1 x^2 \, dx \xlongequal{abc} \frac{1}{3}