\begin{section}{Common}
The function $f$ applied to $x$ is $f\of{x}$. We can group terms
- like $a + \qty{b - c}$ or $a + \qty{b - \sqty{c - d}}$. Here's a
- set $\set{1,2,3} = \setc{n \in \Nn[1]}{ n \le 3 }$. The tuples go
- up to seven, for now:
+ like $a + \qty{b - c}$ or $a + \qty{b - \sqty{c - d}}$. The tuples
+ go up to seven, for now:
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\begin{itemize}
\begin{item}
\end{section}
\begin{section}{Set theory}
- The cardinality of the set $X \coloneqq \set{1,2,3}$ is $\card{X}
- = 3$, and its powerset is $\powerset{X}$.
+ Here's a set $\set{1,2,3} = \setc{n \in \Nn[1]}{ n \le 3 }$. The
+ cardinality of the set $X \coloneqq \set{1,2,3}$ is $\card{X} =
+ 3$, and its powerset is $\powerset{X}$.
We also have a few basic set operations, for example the union of
two or three sets: $\union{A}{B}$, $\unionthree{A}{B}{C}$. And of