eq1 = Eq((cos(x) - sin(y) / 2)**2 + 3 * (-sin(x) + cos(y) / 2)**2, 2)
eq2 = Eq((cos(x) - 2 * sin(y))**2 - (sin(x) + 2 * cos(y))**2, 3)
plot_contour(eq1.lhs - eq1.rhs, eq2.lhs - eq2.rhs, {"levels": [0]},
     (x, 0, 2 * pi), (y, 0, 2 * pi), is_filled=False, clabels=False)
# Expected:
## Plot object containing:
## [0]: contour: 3*(-sin(x) + cos(y)/2)**2 + (-sin(y)/2 + cos(x))**2 - 2 for x over (0, 2*pi) and y over (0, 2*pi)
## [1]: contour: -(sin(x) + 2*cos(y))**2 + (-2*sin(y) + cos(x))**2 - 3 for x over (0, 2*pi) and y over (0, 2*pi)