EXAMPLE $7\mathrm{.}10$

The language

$L=\{a^n{b}^n$:$n0\}$

is a deterministic context$-$free language. The pda $,\{$:$b\},\{0,1\},,q_0,0,\{q_0\}$ with

$(q_0,a,0)=\{(q_1,10)\},$

$(q_1,a,1)=\{(q_1,11)\},$

$(q_1,b,1)=\{(q_2,)\},$

$(q_2,b,1)=\{(q_2,)\},$

$(q_2,,0)=\{(q_0,)\}$

accepts the given language. It satisfies the conditions of Definition $7\mathrm{.}3$ and is therefore deterministic.

My question. Why the given pda is dpda for the language? The language has to accept empty string, but the $($d$)$pda can not accept it$.$