Meta-language is any proposition that speaks another language. Propositions ( significant linguistic expressions that can be true or false ) they can be of two kinds: that speak 40 reality; they constitute 41 language; and that speak 40 language; they constitute the metalanguages ). Therefore there are different levels of truth or falsehood: the 0 level language that speaks of the real, which speaks of the level 0 level 1 level 2 level 1 talking and thus to infinity. These studies of philosophers such as Bertrand Russell and Wittgenstein have been very useful in logic and computer science and have solved the apparent contradictions of the language, like the classic liar: Epimenides, a Cretan, said: all Cretans lie always.?? Epimenides lies or tells the truth?.
