theorem
proved
term proof
divisors_card_onehundredtwenty_gt
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formal statement (Lean)
1401theorem divisors_card_onehundredtwenty_gt : ∀ n, 0 < n → n < 120 → (n : ℕ).divisors.card < (120 : ℕ).divisors.card := by
proof body
Term-mode proof.
1402 intro n hn hlt
1403 interval_cases n <;> native_decide
1404
1405/-! ### Safe primes (p such that (p-1)/2 is also prime) -/
1406
1407/-- 5 is a safe prime: (5-1)/2 = 2 is prime. -/