出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/06/29 02:59 UTC 版)
In mathematical logic, a well-formed formula, shortly wff, often simply formula, is a word (i.e. a finite sequence of symbols from a given alphabet) which is part of a formal language. It is a syntactic object that can be given a semantic meaning. A formal language can be considered to be identical to the set containing all and only its formulas.