$Version

13.0.1 for Microsoft Windows (64-bit) (January 28, 2022)
FullForm[a+b+c]
Output
FullForm[{a,b,c}]
Output
neg3=-w // TeXForm
$$\{-2,-3\}$$
w={2,3}

{2, 3}
fun:= Sin[Sqrt[x^2 + y^2]]/Sqrt[x^2 + y^2]
Plot3D[fun, {x, -5*Pi, 5*Pi}, {y, -5*Pi, 5*Pi},
    PlotPoints -> 100, BoxRatios -> {1, 1, 0.2},
    PlotRange -> All]
Output
$Version

13.0.1 for Microsoft Windows (64-bit) (January 28, 2022)