Definition:Bound Variable/Also known as

Bound Variable: Also known as

A bound variable is also popularly seen with the name dummy variable, but that term has a different definition on $\mathsf{Pr} \infty \mathsf{fWiki}$.

Sometimes dummy letter can be seen.

In treatments of pure logic, this is sometimes known as an individual variable.

Some sources call it an apparent variable, reflecting the fact that it only "appears" to be a variable.

Some authors gloss over the difference between:

a bound variable: a variable which exists in a WFF only as bound occurrences

and:

a bound occurrence of a variable which may otherwise exist as a free occurrence.

Sources

• 1946: Alfred Tarski: Introduction to Logic and to the Methodology of Deductive Sciences (2nd ed.) ... (previous) ... (next): $\S 1.4$: Universal and Existential Quantifiers
• 1955: John L. Kelley: General Topology ... (previous) ... (next): Chapter $0$: Sets
• 1965: Claude Berge and A. Ghouila-Houri: Programming, Games and Transportation Networks ... (previous) ... (next): $1$. Preliminary ideas; sets, vector spaces: $1.1$. Sets
• 1978: Thomas A. Whitelaw: An Introduction to Abstract Algebra ... (previous) ... (next): $\S 3$: Statements and conditions; quantifiers
• 1980: D.J. O'Connor and Betty Powell: Elementary Logic ... (previous) ... (next): $\S \text{III}$: The Logic of Predicates $(1): \ 3$: Quantifiers
• 1996: H. Jerome Keisler and Joel Robbin: Mathematical Logic and Computability ... (previous): $\S 2.1$
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): dummy variable