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The article defines a "projection"

Such a mapping cannot exist. In fact, as this would imply even for a nonzero D.Lazard (talk) 10:12, 19 January 2020 (UTC)[reply]

What you state is correct. The correct way to define it is to choose any element from the preimage of , then take the appropriate coordinate projections and then tensor them. A reference to Landsberg, Tensors: Geometry and Applications, 2012 could be added as a source. Ntheazk (talk) 21:53, 28 January 2020 (UTC)[reply]