What a strange statement&#x2F;article.  I had to check all three of those as an undergrad, associativity of matrix multiplication was definitely first year linear algebra, and I think elliptic curve product was first year number theory.<p>(and it still is, theorem 3.4 in these first year notes <a href="https:&#x2F;&#x2F;wwwf.imperial.ac.uk&#x2F;~kb514&#x2F;M1GLA.pdf" rel="nofollow">https:&#x2F;&#x2F;wwwf.imperial.ac.uk&#x2F;~kb514&#x2F;M1GLA.pdf</a>)<p>&quot;It is that they are felt too tedious or technical to prove in a course or even a textbook.&quot;  Was my degree unusually tedious?