A function that can be "extended" to another function
53358
What does it mean to extend a function?
63701
An example of a regular function over an open set
29647
Do there exist functions satisfying $f(x+y)=f(x)+f(y)$ that aren't linear?
80656
Is it possible to iterate a function transfinite times?
4709
Functions with Options
109942
Find continuous functions such that $f(x+y)+f(x-y)=2[f(x)+f(y)]$
40813
Can a function be made to accept a variable amount of inputs?
2142
Finding a set of continuous functions with a certain property 2
10502
Nested definition: How can I define a function with a passed-in expression?
60697
Defining functions from expressions of variable lengths
16034
Function whose inverse is also its derivative?
153697
Is there a function $f: \mathbb{R} \to \mathbb{R}$ such that $\lim\limits_{x\to p}f(x)=\infty$ for every $p \in \mathbb{R}$
99998
How to call an extended procedure from a function
103654
A finite field extension that is not simple
39090
Finding functions such that $f(g(x)) = f(x)g(x)$
140013
How to extend an existing JavaScript array with another array, without creating a new array
75944
Overlapping pure functions