α_{1} = \frac{X (τ_{1}) y}{∥ X (τ_{1}) ∥} \dots α_{j + 1} = \frac{X (α_{j + 1}) y}{∥ X (τ_{j + 1}) ∥}, α_{j + 2} = \frac{X (τ_{j + 2}) y}{∥ X (τ_{j + 2}) ∥}