Sheep (+1) and goats (−1) share a field, each animal at a spot [x, y]. A straight fence line = [w1, w2, b] splits it: a spot is on the sheep side when w1 * x + w2 * y + b is positive and on the goat side when it’s negative. Write safety(points, labels, line): how safely the fence keeps the herds apart. Negative if any animal is on the wrong side.