unassimilatible writes: "The Boston Globe is reporting that Cyberkinetics Inc. is about to ask federal regulators for permission to start testing a device that would enable paralyzed people to control computers directly with their brains or possibly help them move their limbs. Initially, the device, implanted into the brains of paralyzed people, will help them control a cursor on a screen or play video games. Researchers believe the technology could one day enable paralyzed people to type, control lights and heating controls, maneuver wheelchairs, or even manipulate robotic arms. I, for one, look forward to playing Stephen Hawking in Unreal Tournament 2004."
We warn the reader in advance that the proof presented here depends on a
clever but highly unmotivated trick.
-- Howard Anton, "Elementary Linear Algebra"