I search on the Internet for what a proper function is but cannot find anything very related. Wikipedia has definitions about proper convex function and proper concave function but I don't know whether they are the same as proper functions or not?
What is a proper function?
$\endgroup$ 41 Answer
$\begingroup$I try to search for 'proper map' instead in Wikipedia. The simple version is:
$\endgroup$In mathematics, a function between topological spaces is called proper if inverse images of compact subsets are compact. In algebraic geometry, the analogous concept is called a proper morphism.
