Cadabra
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combine

Combine two consecutive indexbracket objects
Combine two consecutive objects with indexbrackets and consecutive contracted indices into one object with an indexbracket. An example with two contracted matrices:
ex:=(\Gamma_r)_{\alpha\beta} (\Gamma_{s t u})_{\beta\gamma}; combine(_);
\(\displaystyle{}\left(\Gamma_{r}\right)\,_{\alpha \beta} \left(\Gamma_{s t u}\right)\,_{\beta \gamma}\)
\(\displaystyle{}\left(\Gamma_{r} \Gamma_{s t u}\right)\,_{\alpha \gamma}\)
An example with a matrix and a vector:
ex:=(\Gamma_r)_{\alpha\beta} v_{\beta}; combine(_);
\(\displaystyle{}\left(\Gamma_{r}\right)\,_{\alpha \beta} v_{\beta}\)
\(\displaystyle{}\left(\Gamma_{r} v\right)\,_{\alpha}\)
The inverse of combine is expand.
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