Following is my complete code

```
{\mu,\nu,\alpha}::Indices("one").
{a,b,c}::Indices("two").
{\mu,\alpha,\nu}::Indices("three").
V^{\mu?\nu?}::AntiSymmetric.
\nabla{#}::Derivative.
{C^{\nu?\alpha?},V^{\mu?\nu?}}::Depends(\nabla{#}).
{C^{\nu?\alpha?},V^{\mu?\nu?}}::NonCommuting.
ex:=\int{\nabla^{\alpha}{{V^{\mu\nu} \nabla^{\mu}{C^{\alpha\nu}}};
product_rule(_);
substitute(_,$\nabla^{\alpha}{V^{\mu\nu}}->-\nabla^{\mu}{V^{\nu\alpha}}-\nabla^{\nu}{V^{\alpha\mu}}$);
distribute(_);
integrate_by_parts(_, $V^{\mu?\nu?}$);
canonicalise(_);
factor_out(_,$V^{\alpha?\mu?}$);
rename_dummies(_,"one","two");
rename_dummies(_,"two","three");
```

I want to make

$$

V^{\alpha \mu} (-\nabla^{\nu}\nabla^{\nu}{C^{\alpha \mu}}-\nabla^{\nu}\nabla^{\alpha}{C^{\mu \nu}}+\nabla^{\nu}\nabla^{\alpha}{C^{\nu \mu}})=0

$$

become

$$

V^{\mu\nu}(\nabla^{\alpha}\nabla^{\alpha}C^{\mu\nu}+\nabla^{\alpha}\nabla^{\mu}C^{\alpha\nu}+\nabla^{\alpha}\nabla^{\mu}C^{\nu\alpha})=0

$$

where $V^{\mu\nu}$ is antisymmetric.