# Definition:Formal Language/Alphabet/Primitive Symbol

< Definition:Formal Language | Alphabet(Redirected from Definition:Primitive Symbol)

Jump to navigation
Jump to search
## Definition

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

## Sources

- 1965: E.J. Lemmon:
*Beginning Logic*... (previous) ... (next): $\S 2.1$: Formation Rules - 1993: M. Ben-Ari:
*Mathematical Logic for Computer Science*(1st ed.): $\S 1.2$ - 1996: H. Jerome Keisler and Joel Robbin:
*Mathematical Logic and Computability*: $\S 1.2$