As significant mathematics errors appear, they will be logged here. Most of the typographical errors (missing/extraneous spaces, mathematics in non-math font, etc.) are not listed.
$\{\{ n \in \mathbb{Z} \mid n < 0\}, \{0\},\{ n \in \mathbb{Z} \mid 0 < n \}\}$(Found by Conor McNierney)
$\texttt{Binomial[52,13] Binomial[39,13] Binomial[26,13]}$(Found by Rob Beezer)
$\cdots \leq n \lvert Y \rvert $