ABSTRACT

In this section, we recall, in some detail, how to associate subspaces to a matrix A in Cm×n. First, we recall what a subspace is.

DEFINITION 3.1 (subspace of Cn) A nonempty subset M ⊆ Cn is called a subspace of Cn iff M is closed

under the formation of sums and scalar multiples. That is, if u, v ∈ M, then u+ v ∈ M, and if u ∈ M and is any scalar, then u ∈ M.