-----Description----- 
This task requires writing a Lean 4 method that determines whether a given natural number is prime. A number (with n ≥ 2) is considered prime if it is divisible only by 1 and itself. The method should return true when the input number is prime and false otherwise.

-----Input-----
The input consists of:
n: A natural number (Nat) such that n ≥ 2.

-----Output-----
The output is a Boolean value:
Returns true if the input number is prime (i.e., there is no integer k with 1 < k < n that divides n).
Returns false if the input number is not prime (i.e., there exists an integer k with 1 < k < n that divides n).

-----Note-----
The input is expected to satisfy the condition n ≥ 2.