ANSI Common Lisp 3 Evaluation and Compilation 3.1 Evaluation
3.1.3 Lambda Expressions
In a lambda expression,
the body is evaluated in a lexical environment that is formed by
adding the binding of
each parameter in the lambda list
with the corresponding value from the arguments
to the current lexical environment.
For further discussion of how bindings are established
based on the lambda list, see Section 3.4 Lambda Lists.
The body of a lambda expression is an implicit progn;
the values it returns are returned by the lambda expression.