Topology: The Meaning of Symbols
What is this symbol and what does it mean? See attachment.© SolutionLibrary Inc. solutionlibary.com 9836dcf9d7 https://solutionlibrary.com/math/geometry-and-topology/topology-the-meaning-of-symbols-34v
... is open, x has an -neighbourhood lying completely inside Ai and this is also inside A.
2. The intersection of finitely many open sets is open.
It is enough to show this for just two open sets A and B.
So suppose x A ...