Hanc marginis exiguitas non caperet

Pierre de Fermat famously wrote “Hanc marginis exiguitas non caperet” (this margin is too narrow to contain it) about his purported proof that there are no integers $x,y,z>1$, $n>2$ with $x^n+y^n=z^n$.

Marginis is a collection of formal proofs of small observations one might make when reading a mathematics paper, that are simple enough that the margin can contain them.

Marginis is focused on the Journal of Logic and Analysis and its list of 145 (as of June 7, 2024) papers.