Dear all

I have read in a journal paper this equality for the norm of two vectors. Could please anyone tell me if this can be valid and where i could read further about it since I cannot understand it:

Take the norm:

||X-Y||=maxi|xi-yi|

Shouldn't ||X-Y|| be calculated as the Euclidean distance of two vectors and not just the absolute difference of the two largest elements of the vectors?

Thank you very much