Which is indeed their argument. But in that case they haven't proved that $T_c^{zero}$ = 110 K, they only proved that $T_c^{zero}$ < 110 K. (And I should also n

Which is indeed their argument. But in that case they haven't proved that $T_c^{zero}$ = 110 K, they only proved that $T_c^{zero}$ < 110 K. (And I should also note that $T_c^{zero}$ doesn't imply the actual critical temperature $T_c$, while the title strongly suggests so.)