- DOOM (MS-DOS) (archive.org)
The Union Aerospace Corporation has been experimenting with teleportation technology on Mars’ moons Phobos and Deimos. After early successes, something goes wrong. It seems the scientists have opened a gateway straight to Hell. Phobos base is overrun with demonic creatures, and the whole of Deimos simply vanishes. A squad of marines is sent to Phobos, but all except one are quickly slaughtered. It falls to the surviving marine to grab some guns and strike back at the demons.
- Expression (mathematics) (Wikipedia)
In mathematics, an expression or mathematical expression is a finite combination of symbols that is well-formed according to rules that depend on the context. Mathematical symbols can designate numbers (constants), variables, operations, functions, brackets, punctuation, and grouping to help determine order of operations and other aspects of logical syntax.