“…Finally, we would like to comment on potential ideas for categorification of these results. The ring of symmetric polynomials in N variables is naturally categorified by the category of annular gl N -webs, with morphisms given by annular foams [6,32,33,13,11]. By the work of the second author and Wedrich [13], one can interpret it as a symmetric monoidal Karoubian category generated by one object E corresponding to a single essential circle.…”