Stroppel's intrinsic formality conjecture for extended Khovanov arc algebras
Let Kmn{\mathrm{K}}_m^nKmn be the extended Khovanov arc algebra indexed by mmm and nnn, and let HHi−22(Kmn,\operatorname{HH}^2_{i-2}({\mathrm{K}}_m^n,HHi−22(Kmn,{mathrm{K}}m^n)…