$\huge{%n}$

U

补集：∁_UA

l1: {Polygon[(-4, -3), (4, -3), (4, 3), (-4, 3)]}
A = PointIn(Polygon[(-2, -1), (2, -1), (2, 1), (-2, 1)])
c = Circle(A, 2)
a(x, y) = LeftSide[c] > RightSide[c] ∧ -3 < y < 3 ∧ -4 < x < 4