HMS Raven was a Cruizer-class brig-sloop built by Perry, Wells and Green at Blackwall Yard and launched in 1804. Although she embodied some interesting innovations tailored for service in the area of the Straits of Gibraltar, she was wrecked before she got on station and never tested them. Her captain, the innovator, was the subject of a miscarriage of justice at his court martial for the loss of the ship from which his career never recovered.
In mathematical logic, propositional logic and predicate logic, a well-formed formula, abbreviated WFF or wff, often simply formula, is a finite sequence of symbols from a given alphabet that is part of a formal language. A formal language can be identified with the set of formulas in the language. A formula is a syntactic object that can be given a semantic meaning by means of an interpretation. Two key uses of formulas are in propositional logic and predicate logic.