Definition:Falsifiable/Formula

Definition
Let $\mathcal L$ be a logical language.

Let $\mathscr M$ be a formal semantics for $\mathcal L$.

A logical formula $\phi$ of $\mathcal L$ is falsifiable for $\mathscr M$ iff:


 * $\phi$ is not valid in some structure $\mathcal M$ of $\mathscr M$

That is, there exists some structure $\mathcal M$ of $\mathscr M$ such that:


 * $\mathcal M \not\models_{\mathscr M} \phi$

Also see

 * Definition:Satisfiable Formula
 * Definition:Contradiction
 * Definition:Tautology
 * Definition:Contingent Statement