Modalized occurrence

An occurrence of a propositional variable in a modal formula is modalized if it lies within the scope of a box operator. A variable occurs modalized in a formula when all its occurrences do. For example $p$ is modalized in $\square p\to q$, while $q$ is not. Fixed-point and uniqueness theorems for Gödel-Löb logic impose this syntactic condition on the variable being solved for.