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expand_diracbar
Simplify the Dirac bar of a composite object.
Rewrite the Dirac conjugate of a product of spinors and gamma matrices
as a product of Dirac and hermitean conjugates. This uses
\begin{equation}
\bar\psi = i \psi^\dagger\Gamma^0\,,
\end{equation}
together with
\begin{equation}
\Gamma_m^{\dagger} = \Gamma_0\Gamma_m\Gamma_0 \,.
\end{equation}
For example,\bar{#}::DiracBar.
\psi::Spinor(dimension=10).
\Gamma{#}::GammaMatrix.
ex:=\bar{\Gamma^{m n p} \psi};
\(\displaystyle{}\bar{\Gamma^{m n p} \psi}\)
expand_diracbar(_);
\(\displaystyle{}\bar{\psi} \Gamma^{m n p}\)