/ -x -x\
\E - x*e /*sign(x)
$$\left(- x e^{- x} + e^{- x}\right) \operatorname{sign}{\left(x \right)}$$
-x
((-2 + x)*sign(x) - 2*(-1 + x)*DiracDelta(x))*e
$$\left(\left(x - 2\right) \operatorname{sign}{\left(x \right)} - 2 \left(x - 1\right) \delta\left(x\right)\right) e^{- x}$$
-x
(-(-3 + x)*sign(x) - 2*(-1 + x)*DiracDelta(x, 1) + 4*(-2 + x)*DiracDelta(x))*e
$$\left(- \left(x - 3\right) \operatorname{sign}{\left(x \right)} + 4 \left(x - 2\right) \delta\left(x\right) - 2 \left(x - 1\right) \delta^{\left( 1 \right)}\left( x \right)\right) e^{- x}$$