\cdbalgorithm{breakgendelta}{}

Convert generalised delta symbols to products of normal Kronecker
delta symbols with two indices.
\begin{screen}{1,2}
\delta{#}::KroneckerDelta.
\delta_{m}^{n}_{p}^{q};
@breakgendelta!(%);
1/2 \delta_{m}^{n} \delta_{p}^{q} - 1/2 \delta_{p}^{n} \delta_{m}^{q};
\end{screen}
(This is more efficient than projecting with the Young projector and
then canonicalising).

\cdbseealgo{reduce_gendelta}
\cdbseeprop{KroneckerDelta}
\cdbseealgo{young_project_tensor}

