Skip to main content
5 events
when toggle format what by license comment
Sep 16, 2022 at 13:18 comment added Jochen Wengenroth That's awesome. Nevertheless, I think that the standard proof (without transfinite induction goes through): One assumes that there is no minimizer and constructs recursively a sequence $x_n$ with $f(x_{n+1})\le (f(x_n)+c_n)/2$ where $c_n=\inf f(B_n)$ and $B_n=\{y\in X: f(y)\le f(x_n)-d(x_n,y)\}$. This sequence is Cauchy and lower semicontinuity is only used to show that the limit $x_*$ satisfies $f(x_*)\le \liminf\limits_{n\to\infty} f(x_n)$. But the sequence $f(x_n)$ is strictly decreasing so that the limit exists and the inequality follows from lower pseudocontinuity.
Nov 1, 2018 at 12:43 vote accept M. Reza. K
Oct 31, 2018 at 6:24 history edited Taras Banakh CC BY-SA 4.0
added 1 character in body
Oct 30, 2018 at 16:54 history edited Taras Banakh CC BY-SA 4.0
deleted 2 characters in body
Oct 30, 2018 at 16:31 history answered Taras Banakh CC BY-SA 4.0