# Definition:Well-Formed Formula

## Definition

Let $\FF$ be a formal language whose alphabet is $\AA$.

A well-formed formula is a collation in $\AA$ which can be built by using the rules of formation of the formal grammar of $\FF$.

That is, a collation in $\AA$ is a well-formed formula in $\FF$ if and only if it has a parsing sequence in $\FF$.

## Also known as

This is often encountered in its abbreviated form WFF, pronounced something like woof or oof, depending on personal preference.

Other names include well-formed word or simply formula.

Some less formal approaches use the term statement form.

(Well-formed) expression is also seen.