function complex_test()
    c1 = 2 + 3im
    c2 = 4 + 5im
    c3 = c1 + c2
    @assert(c3 == (6 + 8im))
    c4 = c1 + 3
    @assert(c4 == (5 + 3im))
    c5 = c1 + 4im
    @assert(c5 == (2 + 7im))
    c6 = c3 - 2.3
    @assert(c6 == (3.7 + 8im))
end

if abspath(PROGRAM_FILE) == @__FILE__
    complex_test()
    println("OK")
end
