The question's listed below:
Let f be a real-valued function defined on R (real). Show that the inverse image with respect to f of an open set is open, of a closed set is closed, and of a Borel set is Borel.
Thank you so much for the help!
The question's listed below:
Let f be a real-valued function defined on R (real). Show that the inverse image with respect to f of an open set is open, of a closed set is closed, and of a Borel set is Borel.
Thank you so much for the help!