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If $A^iB_i$ is called a contraction, what is $A^{ij}B_{ij}$ called?

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0 I have a tensor $A^{ijk}$ and a tensor $B_{ijk}$ , and I'd like to contract all the indices between them, resulting in the scalar $k$ : $$k = A^{ijk}B_{ijk}$$ Is there a name for this sort of "multi-contraction"? By knowing the name, I'd like to study this type of operation more. I'm not sure whether they occur in the study of differential forms, or tensor algebra, or geometric algebra, or otherwise. reference-request tensors geometric-algebras share | cite | improve this question asked Nov 27 '18 at 21:22 Doubt 738 3 21 ...

Unable to scan in Ubuntu 18.04

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1 I have problem with scanning on LJ M1132 MFP printer/scaner. My search on many various forums did not get anywhere so I try to ask directly if someone can help me. I recently reinstall system from Mate 16.04. to Ubuntu 18.04. In 16.04. the scanner had no problems. After installation of new system I had problems even with the printing. I installed newest hplip. Printing works for some time but scanning was not possible. All the time it show i/o problems. For example "simple scan" shows warning " Unable to connect to scanner ". If I run hp-scan it comes with " error: SANE: Error during device I/O (code 9) " I try several tips, like reinstalling hplip, so now I have instaled 3.18.6 version, but no change in scanning. If I run hp-check -t from my point important par...