Here&#x27;s a link to the referenced paper where Marcus, Spielman, and Srivastava present their proof:<p>&quot;Interlacing Families II: Mixed Characteristic Polynomials and the Kadison-Singer Problem&quot; <a href="http:&#x2F;&#x2F;arxiv.org&#x2F;pdf&#x2F;1306.3969v4.pdf" rel="nofollow">http:&#x2F;&#x2F;arxiv.org&#x2F;pdf&#x2F;1306.3969v4.pdf</a>