\begin{definition}[Definition:Language of Propositional Logic/Alphabet/Sign/Bracket]
The signs of the language of propositional logic include the '''brackets''':
{{begin-eqn}}
{{eqn | ll= \bullet
      | l = (
      | o = :
      | r = \)the '''left bracket''' sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = )
      | o = :
      | r = \)the '''right bracket''' sign\(
      | c = 
}}
{{end-eqn}}
These are used as parenthesis signs.
\end{definition}