'Reinvent' is mostly irrelevant in a patent infringement case. If your invention includes all the elements of a claim in a granted patent, even if you came up

'Reinvent' is mostly irrelevant in a patent infringement case. If your invention includes all the elements of a claim in a granted patent, even if you came up with it in isolation, you're still infringing on that patent. Saying you came up with it in parallel only protects you from treble damages from willful infringement. And patent claims (while flawed works of man and deliberately twisted works of lawyers) are far more precise and narrow than 'unix clone' or 'mp3 player'. Infringing a patent requires something far closer to the original than an iPod to a Nomad or iLife to Office.