Definition:Statement Form

Definition
A statement form is a symbolic representation of a compound statement.

It consists of statement variables along with logical connectives joining them.

It is traditional, particularly in the field of mathematical logic, to use lowercase Greek letters to stand for general formulas (the usual ones being $\phi, \psi$ and $\chi$), but more modern treatments are starting to use ordinary lowercase letters of the English alphabet, usually $p, q, r$ etc.

Formal Definition
A statement form is an expression containing statement variables and logical connectives, formed using the following rules:


 * Any statement variable is a statement form.


 * If $A$ and $B$ are statement forms, then:
 * If $\intercal$ is a unary logical connective, then $\left({\intercal A}\right)$ is a statement form.
 * If $\intercal$ is a binary logical connective, then $\left({A \intercal B}\right)$ is a statement form.

Also known as
There are various names for this concept, for example:
 * statement scheme or schema
 * symbolic sentence
 * logical form.

When discussing propositional calculus, the terms logical formula or propositional formula are also used.

Their Classical plurals are logical formulae and propositional formulae.