The set closure of the set of arguments of a function 
for which 
is not zero.
Support
See also
Set ClosureExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Support." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Support.html