User Portlet User Portlet

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Plot3D[9, {x, -5, 5}, {y, -5, 5}, RegionFunction -> Function[{x, y, z}, x^2 + y^2 0 \[And] y > 0], Filling -> Bottom, AxesLabel -> Automatic] I write like this but it doesn't create a visual from this code
Thank you very much my friend :)