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please see the attached snapshot (taken from 'Problem book in relativity and gravitation'). In the last equation I think there would be no semicolon.

Here is why I believe (S is scalar by the way):

S_{;α[βγ]}= 1/2 * ( S_{;αβγ}- S_{;αγβ})

Now from the equation which precedes it, we have :

S_{;αβγ}= S_{,αβγ}- S_{σ}τ^{σ}_{αβ,γ}

and :

S_{;αγβ}= S_{,αγβ}- S_{σ}τ^{σ}_{αγ,β}

this means :

S_{;α[βγ]}= 1/2 * ( S_{σ}R^{σ}_{αβγ}) due to the first equation of the solution 9.8 on the top of the page.

We see that there is no semicolon. Where did I go wrong if at all ?

Thank you,

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# Covariant derivative - is this a typo ?

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