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Math and science::Algebra::Aluffi
Groups. Lagrange's theorem.
Lagrange's theorem
Let \( G \) be a group, and let \( H \subset G \) be a subgroup. Then:
[\[
|G| = \quad ?
\]]
There are three corollaries on the reverse. Can you remember them?
- About the order of \( g \) in \( G \).
- When \( |G| \) is a prime.
- Fermat's little theorem.
