Definition:Variable/Propositional Logic

Definition
A statement variable is a variable which is used to stand for arbitrary and unspecified statements.

For statement variables, lowercase letters are usually used, e.g.:
 * $p, q, r, \ldots{}$, etc.

or lowercase Greek letters, e.g.:
 * $\phi, \psi, \chi$ etc.

The citing of a variable can be interpreted as an assertion that the statement represented by that symbol is true.

That is:
 * $p$

means
 * $p \text { is true}$

Also known as
Equivalent terms for statement variable are propositional variable and proposition symbol.

The latter name is also used for the letters of the language of propositional logic, which are intended to represent statement variables.

Also see
Note the difference between a statement label and a statement variable.

The first is used to identify a particular statement. The latter is used to represent an instance of any statement at all.