Compatible
Let 
be the Matrix Norm associated with the Matrix 
and 
be theVector Norm associated with a Vector 
. Let the product 
be defined, then and are said to be compatible if
References
Gradshteyn, I. S. and Ryzhik, I. M. Tables of Integrals, Series, and Products, 5th ed. San Diego, CA: Academic Press, p. 1115, 1980.
- Unstable Node
- Unstable Spiral Point
- Unstable Star
- Untouchable Number
- U-Number
- Upper Bound
- Upper Integral
- Upper Limit
- Upper Sum
- Upper-Trimmed Subsequence
- Upward Drawing
- Urchin
- Utility Graph
- Utility Problem
- Valence
- Valency
- Valuation
- Valuation Group
- Valuation Ring
- Valuation Theory
- Value
- Value (Game)
- Vampire Number
- van der Grinten Projection
- Vandermonde Determinant