Definition:Sign


 * Definition:Symbol


 * Mathematical logic:
 * Definition:Sign (Formal Systems)


 * Propositional logic:
 * Definition:Sign of Propositional Logic


 * Permutation theory:
 * Definition:Sign of Permutation


 * Arithmetic, algebra, analysis and so on:
 * Definition:Sign of Number

Also see

 * Definition:Signum
 * Definition:Signum Function
 * Definition:Signature