*Main> main
Add:      5.0 :+ 2.0
Subtract: (-3.0) :+ 2.0
Multiply: 4.0 :+ 8.0
Divide:   0.25 :+ 0.5
Negate:   (-1.0) :+ (-2.0)
Inverse:  0.2 :+ (-0.4)
Conjugate:1.0 :+ (-2.0)