What on earth does this symbol mean here, in this article:
$$\mathfrak{W}(xe^x)$$
After copying and pasting, I find it is supposedly a W, but clearly it has a certain meaning since the article refers to W (Lambert W) and to this symbol very differently, as if it were a constant perhaps, or some function.
Not knowing what the authors mean by this is completely compromising my ability to understand this article!