Consider a channel where either symbol $x_A$ or symbol $x_B$ is transmitted.
The conditional PDFs of $Y$ given $x_A$ and $x_B$ are:
\[
f_{Y|x_A}(y) = e^{-(y+1)}u(y+1), \qquad
f_{Y|x_B}(y) = e^{(y-1)}\left(1 - u(y-1)\right),
\]
where $u(\cdot)$ is the unit step function.
The probability of symbol error is ____________ (rounded off to two decimal places).
