To endow (a vector space, etc.) with a norm.
if v ne 0 then |v| ne 0;
That which is normal or typical.
A high level of performance in a chess tournament, several of which are required for a player to receive a title.
A rule that is imposed by regulations and/or socially enforced by members of a community.
A sentence with non-descriptive meaning, such as a command, permission, or prohibition.
given a scalar k, |kv|=|k|·|v|, where |k| is the absolute value of k;
given two vectors v,w, |v+w|<|v|+|w| (the triangle inequality).
A graduated flexible ribbon used for measuring lengths.