15 commands, each with the package it needs
Abstract
Empty sets, big unions and intersections, and the blackboard-bold number sets. \mathbb and \varnothing need amssymb. Table 1 lists every symbol of the category with its rendered glyph, the command to type and the package to load; each name links to a page with a worked example, and 3 of them to a note comparing the commands that compile.
| Glyph | Command | Package | Page |
|---|---|---|---|
\emptyset | none | Emptyset | |
\varnothing | amssymb | Varnothing | |
\mathbb{N} | amssymb | Blackboard bold N | |
\mathbb{Z} | amssymb | Blackboard bold Z | |
\mathbb{Q} | amssymb | Blackboard bold Q | |
\mathbb{R} | amssymb | Blackboard bold R | |
\mathbb{C} | amssymb | Blackboard bold C | |
\mathbb{F} | amssymb | Blackboard bold F | |
^\complement | amssymb | Complement | |
\bigcap | none | Bigcap | |
\bigcup | none | Bigcup | |
\bigsqcup | none | Bigsqcup | |
\uplus | none | Uplus | |
\biguplus | none | Biguplus | |
\mathcal{P} | none | Powerset |
Table 1. Set symbols in LaTeX: glyph, command, package (none means built into LaTeX) and the page for each symbol. Commands go inside math mode unless the page says otherwise.
The same table exists for every family of symbols. To find one by name or by pasting the character, use the symbol search.