\[ \begin{array}{l} \text{1. Choose an integer } n \text{ that we want to test.} \\ \text{2. Determine integer } k \text{ and odd integer } m \text{ by solving } n - 1 = 2^k \cdot m. \\ \text{3. Choose an integer } a \text{ such that } 1 < a < n - 1. \\ b0 = a^m \mod{n}. \quad b_0 \equiv \pm 1 \implies n \text{ is probably prime by FLT.} \\ b_1 = b_0^2 \mod{n}. \quad b_1 = -1 \implies n \text{ is probably prime by FLT.} \quad b_1 = 1 \implies n \text{ is composite.} \\ b_2 = b_1^2 \mod{n}. \quad b_2 = -1 \implies n \text{ is probably prime by FLT.} \quad b_2 = 1 \implies n \text{ is composite.} \\ \vdots \\ b{k-1} = b{k-2}^2 \mod{n}. \quad b{k-1} \neq -1 \implies n \text{ is composite.} \end{array} \]