I Background in Linear Algebra

In this section we state some elementary results that we will use for our main proofs. The next Lemma is part of the proof of [44, Lemma 4.2], which we state here as a separate result to save some space from the longer proofs that follow later. This is part of the proof of [44, Lemma 4.2]. In this section we specialize the definitions to the case of Gaussian matrices. Lemma 7. Let n 1 be an integer, and δ (0, 1/2) .