\begin{definition}[Definition:Language of Propositional Logic/Alphabet/Sign/Connective]
The signs of the language of propositional logic include the '''connectives''':
{{begin-eqn}}
{{eqn | ll= \bullet
      | l = \land
      | o = :
      | r = \)the conjunction sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = \lor
      | o = :
      | r = \)the disjunction sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = \implies
      | o = :
      | r = \)the conditional sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = \iff
      | o = :
      | r = \)the biconditional sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = \neg
      | o = :
      | r = \)the negation sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = \top
      | o = :
      | r = \)the tautology sign\(
      | c = 
}}
{{eqn | ll= \bullet
      | l = \bot
      | o = :
      | r = \)the contradiction sign\(
      | c = 
}}
{{end-eqn}}
These comprise:
* The nullary connectives $\top$ and $\bot$, representing the canonical tautology and contradiction, respectively
* The unary connective $\neg$, representing negation
* The binary connectives $\land, \lor, \implies$ and $\iff$, representing, respectively, conjunction, disjunction, implication and biconditional.
\end{definition}