# Definition:Metalanguage/Metasymbol

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## Definition

A **metasymbol** is a symbol used in a metalanguage to represent an arbitrary collation in the object language.

**Metasymbols** are deliberately taken from a set of symbols that are **not** in the alphabet of the object language in question.

On $\mathsf{Pr} \infty \mathsf{fWiki}$, **metasymbols** are usually taken from any of:

- uppercase letters: $P, Q, R, \ldots$ and subscripted versions: $P_1, P_2, \ldots$
- the Greek alphabet: $\phi, \chi, \psi, \ldots$ and their subscripted versions: $\phi_1, \phi_2, \ldots$
- uppercase bold: $\mathbf A, \mathbf B, \mathbf C, \ldots$ and their subscripted versions: $\mathbf A_1, \mathbf A_2, \ldots$

Which system is in use on a particular page depends to a certain extent on the nature of the source work which has inspired it.

## Also see

Altenative terms for a **metasymbol** are:

**metalogical variable****metalogical symbol****metasyntactic variable**^{[1]}.

## References

- ↑ As immortalized by Terry Pratchett in
*Men at Arms*: the dog Gaspode says, "Clothing has never been what you might call a thingy of dog wossname." Then he adds: "Two metasyntactic variables there. Sorry."

## Sources

- 1959: A.H. Basson and D.J. O'Connor:
*Introduction to Symbolic Logic*(3rd ed.) ... (previous) ... (next): $\S 4.2$: The Construction of an Axiom System - 1965: E.J. Lemmon:
*Beginning Logic*... (previous) ... (next): $\S 2.1$: Formation Rules