How do I define an open set using only the four axioms of topological neighborhoods, as per the Wikipedia article on topological spaces?
The intuitive definition of an open set is that it's a set of points on a real number line containing only points at which there is room for some hypothetical...
I am struggling to define an open set using the four axioms of a topological neighborhood, as per the Wikipedia article "Topological spaces."
An open set on a real number line is a set of points that contains only interior points, meaning that there is always room for some hypothetical particle...