If screw-driven steamships generally carry the prefix 'SS' before their names, what type of steamers carry the prefix 'PS'?
Steam-powered vessels 20th century Screw-driven steamships generally carry the ship prefix "SS" before their names, meaning 'Steam Ship' (or 'Screw Steamer' i.e. 'screw-driven steamship', or 'Screw Schooner' during the 1870s and 1880s, when sail was also carried), paddle steamers usually carry the prefix "PS" and steamships powered by steam turbine may be prefixed "TS" (turbine ship). The term "steamer" is occasionally used, out of nostalgia, for diesel motor-driven vessels, prefixed "MV". Steam can be generated with the use of heat produced by nuclear fission within a nuclear reactor. Systems that incorporate nuclear components are found almost mostly onboard military vessels due to
Prefix grammar Prefix grammar In theoretical computer science and formal language theory, a prefix grammar is a type of string rewriting system, consisting of a set of string rewriting rules, and similar to a formal grammar or a semi-Thue system. What is specific about prefix grammars is not the shape of their rules, but the way in which they are applied: only prefixes are rewritten. The prefix grammars describe exactly all regular languages. A prefix grammar "G" is a 3-tuple, (Σ, "S", "P"), where For strings "x", "y", we write "x" → "y" (and say: "G" can derive "y" from "x" in