EPOC is a discontinued family of graphical operating systems developed by Psion for portable devices, primarily PDAs. EPOC came from epoch, the beginning of an era, but was backfitted by the engineers to "Electronic Piece Of Cheese". It was succeeded by Symbian in 1998. Using only the above description and what you know about the world, ""Electronic Piece Of Cheese" was used to remember EPOC." is definitely correct, incorrect, or inconclusive? 