Abstract:
In 1972, it was announced by Averbukh and Smolyanov that $\mathrm{HL}$-differentiability is equivalent to $\mathrm{FB}^\sharp$-differentiability. The proof has not been published till now. Here we prove a stronger result, namely, the one formulated in the title.
Keywords:filter, pseudotopology, differentiability, differentiability in the sense of Frölicher and Bucher, in the sense of Michael and Bastiani, and in the sense of Hyers and Lang.