English
Two groups of the same prime order p are isomorphic.
Русский
Две группы порядка простого числа p изоморфны.
LaTeX
$$$\text{Card}(G)=\text{Card}(G')=p\ \Rightarrow\ G \cong^* G'$$$
Lean4
/-- Two groups of the same prime cardinality are isomorphic. -/
@[to_additive /-- Two additive groups of the same prime cardinality are isomorphic. -/
]
noncomputable def mulEquivOfPrimeCardEq {p : ℕ} [Group G] [Group G'] [Fact p.Prime] (hG : Nat.card G = p)
(hH : Nat.card G' = p) : G ≃* G' := by
have hGcyc := isCyclic_of_prime_card hG
have hHcyc := isCyclic_of_prime_card hH
apply mulEquivOfCyclicCardEq
exact hG.trans hH.symm