a = -1.8 (slider from -5 to 5)
b = 0.2 (slider from -5 to 5)
c = ImplicitCurve((x^(2) + y^(2) - a^(2))^(3) - (((4 * a) * x^(2)) * y^(3)))
d = ImplicitCurve(cos(x - y) - ((b * x) * y) + sin(x + y))