Definition:Formal Language/Alphabet/Primitive Symbol

 Let $\mathcal A$ be the alphabet of a formal language $\mathcal L$.

The symbols which comprise $\mathcal A$ are called the primitive symbols of $\mathcal A$.

It is usual, during the development of a formal system, to introduce further symbols in order to abbreviate what would otherwise be unwieldy constructions.

Hence the distinction between these newly-introduced symbols and the primitive symbols.

Also known as
Some sources do not bother with the word primitive and instead refer to the elements of $\mathcal A$ just as symbols.

Also see

 * Definition:Undefined Term
 * Definition:Definitional Abbreviation