angry tapir writes: "One Laptop Per Child is back in the tablet race, announcing a new 7-inch tablet with the Android OS that will be sold commercially and include its learning software. The XO Tablet was announced at the International CES show in Las Vegas. OLPC will license the design to Sakar International, which will sell the tablet in the U.S. through Wal-Mart."
We warn the reader in advance that the proof presented here depends on a
clever but highly unmotivated trick.
-- Howard Anton, "Elementary Linear Algebra"