cu'ai VUhU3 experimental cmavo

binary mathematical operator: vector norm/magnitude of vector a in structure (normed vector space) b.

Contextless default for b: Euclidean normed vector space over the reals or complexes; in relativity, without context, the default interpretation for a four-vector is the Minkowski magnitude. b determines the meaning of the norm. Accompanies and clarifies " |a|.">cu'a".