sign(x) x*e
x*exp(sign(x))
sign(x) sign(x) 2*x*DiracDelta(x)*e + e
/ / 2 \\ sign(x) 2*\2*DiracDelta(x) + x*\2*DiracDelta (x) + DiracDelta(x, 1)//*e
/ 2 / 3 \\ sign(x) 2*\3*DiracDelta(x, 1) + 6*DiracDelta (x) + x*\4*DiracDelta (x) + 6*DiracDelta(x)*DiracDelta(x, 1) + DiracDelta(x, 2)//*e