Tropical numbers are the same as real numbers, except the operations are different. You can compound these operations, and get tropical vectors, tropical matrices, etc. This package is a Haskell library dealing with tropical things.
For more information on tropical geometry, see https://en.wikipedia.org/wiki/Tropical_geometry.
Anyone who wants to contribute is more than welcome. This library is BSD-licensed, so you can pretty much do what you want with it.