= Grassmann derivative
{c}
{title2=$\partial_\theta^L,\quad\partial_\theta^R$}
A <Grassmann derivative> is an odd differentiation operation on a <Grassmann algebra>. A <left Grassmann derivative> obeys $\partial_\theta^L(ab)=(\partial_\theta^La)b+(-1)^{|a|}a(\partial_\theta^Lb)$ for homogeneous $a$. Right derivatives use the corresponding right-sided product rule. Their placement must be fixed when differentiating fermionic sources in a <generating functional>, since commuting ordinary derivatives would lose <fermionic signs>.
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