- A
**v**=**0**

In set notation, Null A = {**v**: **v** is in **R**^{n} and A**v** = **0** }

The right singular vectors of *A* corresponding to zero singular values form an orthonormal basis for the null space of *A*. The dimension of this linear subspace is called the **nullity** of *A*. This can be calculated by the number of nonleading columns in the row echelon form of the matrix. The rank of any matrix plus its nullity equals the number of columns of that matrix - this is the **Rank-Nullity Theorem**.