# Alpha conversion

### From HaskellWiki

An *alpha conversion* (also written *α conversion*) is a renaming of variables.

For example, suppose we have an expression such as

\x y -> 2*x*x + y

and we change this to

\a b -> 2*a*a + b

This is clearly the same function, even though it uses different variable names. This process of renaming variables is *alpha conversion*.

*name capture*. For example, if we rename

x

y

\x -> x + y

\y -> y + y

Some compilers include an alpha-conversion stage to rename all program variables such that variable names become unique. (This simplifies subsequent processing somewhat.)

Also see Lambda calculus and the wikipedia lambda calculus article.