For z ∈ ℝᴷ, softmax(z)[i] = exp(z[i]) / Σ exp(z[j]). Identity: softmax(z) = softmax(z - max(z)). The safe form keeps every exp input ≤ 0, no overflow.
Temperature T divides logits before softmax. Low T → peaked (deterministic). High T → flat (diverse). T=0 corresponds to argmax (greedy).