Debugging

\[\begin{eqnarray}i\hbar{\partial\over\partial t}G(\xbf,t;\xbf\Prime,t\Prime)&=&  
\langle0|i\hbar{\partial\over\partial t}\psi(\xbf,t)\psi^{\dagger}(\xbf\Prime,
t\Prime)|0\rangle\theta(t-t\Prime)+i\hbar\langle0|\psi(\xbf,t)\psi^\dagger(\xbf\Prime,t\Prime)|0\rangle
\delta(t-t\Prime)\\
&&+i\hbar \langle0|\psi^{\dagger}(\xbf\Prime,t\Prime){\partial\over\partial t} \psi(\xbf,t)
|0\rangle\theta(t\Prime-t)-i\hbar\langle0|\psi^\dagger(\xbf\Prime,t\Prime)\psi(\xbf,t)|0\rangle\delta(t\Prime-t)\\
&=&-{\hbar^2\over2m}\nabla^2\langle0|\psi(\xbf,t)\psi^\dagger(\xbf\Prime,t\Prime)|0\rangle\theta(t-t\Prime)-{\hbar^2\over2m}\nabla^2\langle0|\psi^\dagger(\xbf\Prime, t\Prime)\psi(\xbf,t)|0\rangle\theta(t\Prime-t)\\
&&+i\hbar\langle0|\big[\psi(\xbf,t),\psi^\dagger(\xbf\Prime, t\Prime)\big]|0\rangle\delta(t-t\Prime)\end{eqnarray}\]