plot(
    (sin(x), (x, 0, pi), "a"),
    (cos(x), (x, -pi, pi), "b", {"linestyle": "--"}),
    n=500)
# Expected:
## Plot object containing:
## [0]: cartesian line: sin(x) for x over (0.0, 3.141592653589793)
## [1]: cartesian line: cos(x) for x over (-3.141592653589793, 3.141592653589793)