ANSI Common Lisp   3 Evaluation and Compilation   3.4 Lambda Lists

3.4.7 Defsetf Lambda Lists

A defsetf lambda list has the following syntax:

lambda-list::= {var}*
[&optional {var | (var [init-form [supplied-p-parameter ]])}^*]
[&rest var]
[&key {var | ({var | (keyword-name var)} [init-form [supplied-p-parameter ]])}^* [&allow-other-keys]]
[&environment var]

A defsetf lambda list can contain the lambda list keywords shown in the next figure.

A defsetf lambda list differs from an ordinary lambda list only in that it does not permit the use of &aux, and that it permits use of &environment, which introduces an environment parameter.